Go Kart Engines: Predator 212cc Performance

predator 212cc engine with performance parts

If you came to this page you are probably looking for a go kart engine or a predator 212cc engine, you are in luck. I have been upgrading and building go karts for years and have some engine buying advice for the racer, or novice yard kart driver. Lets have a look at the options for performance mods & stock engines:

Go Kart Engines

Most go kart engines fall into the category of race karts, or fun /  yard karts. That lines have blurred with the advent of cheap Chinese  predator 212cc go kart engines.

Go kart engines can be used for racing or just putting around the yard depending on what performance parts (or mods) that you upgrade.

There are many small industrial 4 stroke engines you can use, but who cares about them. Lets skip all those, and just go straight to the cheapest, and very reliable go kart engine: the predator 212cc 6.5 hp engine.

Predator Engines

Predator engines have destroyed the competition. Because they are so inexpensive, predator engines have opened a whole new world to go karters. They are cheap, and can easily be modified for ad212cc predator engineded performance.

Predator engines literally bolt right on to virtually all standard go karts ever made. The bolt mounting pattern is universal.


If you have an old go kart you need to restore, you can simply buy a predator 212cc engine (amazon link) and breath new life into an old go kart. This engine is a performer right out of the box, and should get your go kart running anywhere from 20 mph all the way up to 35mph in its stock form. But we cant leave well enough alone can we? Let’s get to the modifications.

Predator 212cc Engine Performance Parts

Predator 212cc engines can have their stock parts removed, and replaced with performance parts (parts that increase horsepower and speed compared to the stock predator 6.5 hp engine). Here is a quick overview of what I recommend doing first.

predator 212 performance intake and exhaust kit
predator 212 performance intake and exhaust kit

Engines need three things: air, fuel and spark. When you add more air and fuel into an engine, you get more torque and horsepower, which is the cheapest bang for your buck.

predator 212cc high flow intake adapter and air filter
predator 212cc high flow intake adapter and air filter

Intake The stock air filter and intake keeps the engine from ‘breathing in’ too much air. The less restriction you have for the engine’s air intake, the more air and fuel will enter the combustion chamber. A predator 212cc high flow intake adapter and high flow air filter literally bolt on to the existing carburetor and require no more than a wrench and screwdriver to install. This will give you extra power when you step on the gas.

predator 212cc performance exhaust pipe high flow header
predator 212cc performance exhaust pipe high flow header

Exhaust The stock predator muffler keeps the engine from ‘breathing out’ too much air. If you have lots of  air coming into the engine, you need to release it with little resistance for added performance. That’s when the predator 212cc performance high flow exhaust header really comes into play. You are now able to shove air and fuel quickly into the engine, and release it with little resistance, adding some serious horsepower and torque that you can FEEL when you step on the gas.

Re-Jet With all the air you are putting into the engine, you may also need to drill out the jet a little bigger. Making the hole in the jet larger will allow more fuel to enter the combustion chamber, preventing a ‘lean’ condition that overheats and destroys engines when they have the governor removed. If you have the intake and exhaust complete, go ahead and drill out the jet. Most people use between a #36 and #38 jet in conjunction with the predator 212cc performance parts. If this is something you are not comfortable doing, you can always search for a jet and install one like I did in this short video below.

Remove Governor The governor does what it is named after. It governs the rotations per minute (RPMs) of the go kart engine. Removal is kind of difficult as you will need to open up the crankcase cover, remove the governor, plug the hole you created, and hook up a direct throttle afterwards. Sound complicated? Heres a video. If you are not comfortable doing this, you can REALLY mess up an engine by improperly removing the governor, dropping lifters, or bending valves because you didn’t know what the heck the engine timing was all about and didn’t line up the camshaft dots. Does any of this not make sense to you? If so, scroll below the video for the answer.

Not mechanically inclined? Small engines are perfect to learn on as they are very simple. You can find a standard predator212cc engine online, then work your way up with mods by replacing the intake, exhaust, jet,  and disconnecting the governor. It is up to you what you would like to do, and I have added just enough information here for you to get into the go kart engine scene. Good luck and have fun zooming around in your modded predator 212cc performance go kart engine!

243 thoughts on “Go Kart Engines: Predator 212cc Performance”

  1. I’m building the fixed axel two seat go kart from the plans and was wondering if the 6.5hp 212cc engine was the biggest one that would fit on the kart, or could you go bigger and more powerful without messing up the torque or running out of space?

    1. A few people have put the predator 420cc with bolt on 40 series torque converter on it, and it mounts to the existing plate if you got the standard or deluxe live axle kit. You may need to tack weld the plate on and possibly move it back a tiny bit so the seat slides backward, but it definitely fits. The kart is really torquey and can do donuts easily in dirt with that engine. Same top speed though (33-35 mph)

  2. Hey Kartfab I have a problem with my Hemi 212. I removed the govenor than put some carb/injector cleaner in the tank. I put it back in the bike and started it up. It ran real high in choke than ran like absolute trash in run. I would hit the gas and it would sputter and not get any fuel or combustion but when i let off it idles fine. ???? Do fuel additives affect the energy that gas contains?

    1. The cleaner stuff is garbage. You should never use it in that instance. Plus you have no need for it anyway since it’s not fuel injected. Also, the concentration used in a 10 gallon tank vs maybe half gallon is something to think about. You probably just ruined your gas by adding too much. Empty your entire tank, and clean your carb like you should (if it’s dirty) then use regular pump gas. Fuel additives are not in any way beneficial to your engine, nor is higher octane (premium gas) unless you had your compression ratio changed to 10:1-11:1. The only additive I use in my gas is the fuel stabilizer that helps reduce the harmful effects of ethanol and keeps it fresh for up to 1 yr. it’s called ‘Stabil’

  3. I am having trouble with my mini bike that I put a predator 212 on. I did the performance upgrades, but now everytime I start it up, it runs for a few seconds, and then dies. if I try to unchoke it, it stalls immediately. Also, when I can get to the throttle fast enough, when I rev it it just sputters, revving high, and then low, and then high, and so on.
    I will leave a link to a video of my problem:

    1. Your governor arm is acting funny, like it’s engaging too soon. Did you jack up your governor linkage or governor arm bolt? You can adjust or remove it at this point… Might want to remove it and try a direct linkage. I’m not sure what you did, but it could be running lean. Did you rejet? Are all carb gaskets installed properly? Carb clean?

  4. Hi I have the preditor 212. Engine only runs with choke on. I’ve cleaned the carb and checked for air leaks but everything seems sealed. When choke id turned off engine dies unless already full throttle. Also the air filter box seems to be blowing air when filter is off and intake is open. Bought used

    1. check gaskets from the intake side all the way in. There is also a gasket that people seem to lose between carb and airbox. Sometimes gaskets are reversed accidentally. Next, clean your carb for real. Take out emulsion tube and jet. Also pilot jet etc. Could be the idle pilot jet.Its just running lean, and you gotta figure out why its running lean, which usually is an air leak after the carb, or partially blocked jet(s).

  5. Building a 212cc bicycle now using a26in Schwinn Blackwell…..I ordered the small pipe and high flow air filter with jet change…. also got a torque converter… trying to figure out the proper gear ratio

  6. When removing the stock airbox, there are 2 hoses. the gas tank vent and the crankcase ventilation hose. Installing an aftermarket air filter will not have a place to plug those hoses in. So what would you recommend to do with them? Im wondering if I could just put on tiny air filters for both connections

    1. the tank hose is a one way check valve, so you dont have to do anything with it actually. The crankcase vent hose should be vented to a catch can, or you could put a little air filter on it.

    2. I used a hole punch and put holes in the rubber base if the new filter. Had to get a longer hose for crankcase vent. Thenjoy I sealed the hose in with silicone. Have put about 5 hours on it with no issues.

  7. i have a predetor 6.5 hp 212cc motor on a mini bike ,ive installed the high peformance air filtr and exhaust and rejetted the carb ,also have removed the govenor. After about ten runs around the block {not all at one time} the piston slammed the plug put a hle in the piston and bent a valve and a pushrod.any suggestions on how to prefent it from happening again?

    1. Hmm something is not adding up. If you over rev the engine, you could get valve float which can cause what you explained in an OHV engine. If you plan on taking the engine up to about 5500 rpm, you could get by with heavy valve springs, and a billet stick length connecting rod. If you rev past that you could spin or grenade your flywheel.

      1. You would need to test it on a dyno. Anybody that says othwerwise without the dyno numbers is just making stuff up. Also, HP is dependent on rpms, and there is no real ‘standardized’ way of reporting hp across brands. E.g. hp at 3600 rpm vs 5252 rpm vs peak torque. All of this is modified by modifying the engine.

  8. Should the clutch have some play? Goes in and out like 1/2″. Chain keeps coming off. Couldn’t move the motor anymore forward so took off a link and adjusted the motor and still poppped off.

    1. some clutches have a set screw on them. If the clutch has play in it and you cant secure it with a set screw, then you need to get a spacer to push up against the clutch, then a flat washer against the spacer, then the bolt to secure it all to the engine shaft.

  9. My son is rebuilding his go kart for a high school class. The Predator isn’t certified for CA, and the school has denied his request for it the funding to get the motor because of that. What do you recommend?

    1. I reccomend getting the ‘CA certified’ motor. There are different versions on harborfreight.com so you just have to look around and find the right one.

      1. This is the only way I know how to post here, but I have this engine in a go kart and when you make hard right turns it shuts down. Pull the cord and it fires right back up. I figured maybe not enough oil in the case and it’s rushing away from the sender but you can only get so much oil in it from the two filler caps. Any thoughts?

        1. Disconnect the low oil sensor. Look for a wire coming out of the base of the block, its a bullet connector (ususally yellow wire). Just check your oil before you ride it. I do this on all the go karts I fix up.

  10. I have a predator 212 I put an air intake, preformance exhaust, re jet the carb #36 with the emulsion tube that came with the jet kit. With these mods ran great. When I put the 8* timing key on the flywheel shaft ran good for about ten min now it won’t start and some times rips the starter chord out of my hand what happened?

    1. Could be any number of things but I bet you didn’t torque the flywheel down to 65 ft lbs, and you sheared the timing key. Take off the flywheel and see what happened. Also, could be valve lash.

  11. Hey love the thread and the simplicity to get your cart to the next level provided by the site thanks! I have installed the intake exhaust and rejetted the carb. Runs awesome! I have just removed the gov also. And ordered the billet rod and flywheel. I have read some about cam and spring upgrades. How much more could i get with those? And also what about an entirely new carb. Your recommendations are greatly appreciated. Go Kartfab!!!

    1. Ok so with the governor removed I definetly got more rpms. Towards the top of the rpm range it seems to lose power and not gain speed even though it gets loader. Is this because the valves are not closing fast enough? Floating? If i put in stronger springs woyld it let the engine build more rpms? And if so how much stronger a spring would i use over stock while not robbbing the engine of horsepower?

        1. I will probably mod this thing all the way out over the course of the next few months. Need to know where i go next. This is a street cart. Murray two seater. Its already fast for a gocart but i would willingly take it to an extreme level. Once i built tgis thing to the maximum and am confident in my abilities i will build something bigger. Probably the 13.

        1. So i get a cam that is 8° advanced since the billet flywheel is 8°? Do i need billet valves or are the stock ones fine? And are the 18lb springs enough? Thanks.

          1. No any cam you buy will have a dot on it line that dot up with dot on crank gear. Only thin you need look at is what timing and springs that cam requires. And what ever fits the rest of your build

          2. So there are a plethora of cams to choose from im going to get the 380 with the valve cover spacers and it comes with the springs however it does not indicate timing requirements. Will it work with the 8° advanced timing my flywheel already has? And if the lobes do not clear the crank what are my options?

        2. Hi i have a predator 212 with header intake billet fly wheel with 32 degrees timing advance cam springs lifters restricter plate and its running on alcohol. Im sick of destroying bully clutches. The rebuild on one is 125 and new is over 350. Im looking for a old bell style clutch with atleast a 4500 rpm stall. And i cant seem to find one. Any suggestions?

          1. You need to go and talk to a guy at a kart shop. Those bully clutches dont grenade like that unless you are using them in a way they were not intended to be used, or not maintaining them properly. Problem is not the clutch, problem is misapplication of clutch use.

            With that said, take a look at the golf cart style clutches. You may need to put 3/4″ to 1″ adapter on it, but the comet 780 is good for up to 7000 rpms and can handle all the hp you can jam into the predator 212. keep in mind that if you do use a torque converter, you will lose hp through parasitic drag. The disc clutch is superior to a torque converter in this regard so you will lose out bigtime if you are putting a torque converter on an engine and racing around. also, if you look at GTC industries, they are reviving the comet 340 series torque converter, which is a smaller lighter duty version of the comet 780 built for the 3/4″ shaft engines and jr dragsters back in the day. No gurantee of its usefulness on a modified engine though so you may need to contact them as well.

      1. Your springs are floating I looked up “hemi swap on 212cc predator motor” and a nice vid came up t hhat goes in to detail about what springs are the best for th re motor that’s where I’d look

      2. Don’t run it high with a stock flywheel and rod!! It’ll explode and you could get injured. If you plan to run stronger springs which will, yes, allow you more rpm’s, then please upgrade to a billet flywheel and rod. They are designed to handle the higher rpm’s.
        Btw, the reason it won’t go any higher is because you’re floating the valves….basically, the springs are battling so much force that they can’t close the valves which is why you get stronger springs.

  12. Ok im completely new and wanted a hobby as well as some fun… I recently got a 212cc and havent done any mods yet to it. First off im gonna get a torque converter and upgrade air filter…. I would really like to know what exhaust system would be great for quiet… Also can anyone tell me where to get the hemi cover with the breather.. And exactly what all do i need to do to instal it

  13. I got a new camera for my engine and I’m not sure how it’s supposed to fit in I took the old one out by taking out the rods and pushing in pins but now when I put the new one in and put it all back together it dosent get held in place by the pins and rods in other words I can just pull it out its this ok it’s a height 212 and I bought the performance kit for it for omb warehouse plz help

  14. Hey KartFab, I removed the governor on my predator and now when the choke is off the engine throttles way up on its own without me touching the throttle. Any ideas?

      1. I have linkage from the throttle arm to the top of the carb and the throttle arm returns to the idle position. Yet when the throttle is in idle and we turn off choke it revs up and begins driving!

      1. No they don’t. Most centrifugal clutches handle the extra hp. Comet clutches have a max HP and max RPM rating on them, when you exceed that you shred belts, break sheaves, shear metal off of the drive hubs, and sometimes the drive unit flies apart.

    1. You cannot make that comparison, because engines are not “fast” they rotate a shaft (measured in rotations per minute) and produce torque, and how you gear a go kart with a particular engine, and transmission determines how fast the go kart will go.

  15. I put on air filter and breather filter where do the vacuum lines from the top of the gas tank go if I add a breather filter to the crank case?

    1. The line from the top of the tank is just for EPA purposes to recover fugitive vapors. The line has a one way check valve connected to it. You don’t have to do anything with that line. The valve cover breather can be vented to atmosphere as well. The reason people put filters on them is to keep the oil from spewing everywhere if it gets up that high on a corner. A lot of people don’t even put filters on them, instead, they run the lines to a can that collects the condensate called a catch can.

  16. I don’t know anything about these engines but I want to learn. The predator 212 seems very popular but which one is better and what is the difference hemi and no hemi?

    1. hemi is better, but the difference in performance isnt that big. The valve cover is different with the hemi (cast) vs non-hemi (stamped steel). Main difference is the head.

  17. When it comes to billet rods should i purchase stock length or +.020 rod ive read the little bit larger rod is drop in also with out any other modification is this true im trying to get the best bang for the buck already purchased the billet flywheel ?

    1. It depends. If you have to ask that question, you should do more research and measure on your own. If you get a +.020 and keep the same piston, your piston could pop up out of the block an extra .020. Depending on a ton of other factors (cam, gasket, rockers, timing) you may end up with the piston hitting something else and ruining yoru engine. Simple question, should I? Simple answer, it depends.

    1. You dont have to but in my opinion i would upgrade it , it allows a finer more consistent stream of fuel to the carb .

  18. Im running a 2 hole e tube with a .038 jet on my 212 predator with intake and header is there an all around better fuel setup i can be using and if not what size low end jet should i use ?

    1. Have you read the plug? Seems like it would run rich with that size of jet. All around better fuel setup would be to get a mikuni 22 mm carb w/adapter. They have ones that bolt right onto the predator and you dont have to jack with the throttle linkage as the cable attaches directly to the top of the carb.

      1. Kartfab just checked plug today does seem to be running rich do you think a 140 e tube and 35 36 jet is a better option also will be looking into the carb you mentioned another question at what hp should i start thinking about a torque converter do i need one ?

  19. hey kartfab…gotta question…..my predator 212 ..custom air/exhaust…upgraded jet….i got some 26 # valve springs,are they too stiff for a stock engine?…should i go down to 18#?..i want to avoid the mod 2 cam,as i dont want it to sound like a racer engine and it makes crazy power as it is

    1. any springs that are heavier than stock will rob horsepower until right before they float. 26 is a lot, and completely unnecessary. Just to give you some perspective, box stock racing engines only use 10.8 lb valve springs, which limit the rpm to around 6000, so anyting more than that is overkill for what you are doing. Most times, if you buy a camshaft that is a performance cam, you will get a card with that cam that tells you what you need to set your valve lash to, timing to, and what valve springs to use.

  20. how much more hp will taking the gov out? I have a predator on a mud motor can I get away will just taking the gov out or do I have to do the fly wheel and rod??

  21. i have a predator on a mud motor. its all stock and i average about 11 mph with just two people in my boat.. i would like to get up to 15 loaded with 2 people and gear for duck hunting. how muxh poower does just taking the governer out make? and or just doing an air filter jet and header? and then both combinded? dont wanna spend a but load of money! or i could just buy a bigger hp engine
    thanks in advanced!!

    1. so to answer both of your questions, you get the cheapest AND most hp gains from just doing high flow exhaust and intake with rejetting. You can remove governor, and put a cheap tachometer on there. The rod will break first before the flywheel. Do not put in heavier valve springs if you plan on keeping in the stock rod and flywheel.

  22. So I was about to remove my governor but then I heard that doing that can blow my engine. Is there anything I could do to make it not blow up but still be able to àgo at fast speeds with my kart

  23. I started out building the standard gokart and decided midway to upgrade to live axle with disc brakes and the larger rear wheels. Do I need to also upgrade to the torque converter?

  24. I want to know if I take a non hemisphere air box and muffler and add them to my hemisphere how does this help me when racing the stock predator class

  25. Hello my question may have been asked but I didn’t see the thread if so. I have a Predator 212 non hemi and I bought a high flow intake and filter and installed it onto the engine. I noticed very quickly that it was not running very well and I immediately knew that it was the jet so I bought a drill bit to the exact recommended size and drilled out the jet. That didn’t help at all so I moved onto buying the better built carburetor that you can change the fuel air mixture on and tried the jet I redrilled and that didn’t work so I tried the new one and then tried redrilling the new one and nothing worked. Would it be safe too assume that self drilling the jets doesn’t work properly or do you think it could be something else?

    1. if you put a high flow intake and filter on it, you gotta put the performance exhaust on it. That is your problem. Also, you cant just go drilling holes. Try a 0.035″ jet with a gx140 emulsion tube.

  26. My 212 cc predator engine started making a REALLY REALLY loud grinding noise when i press the gas. What is my problem?

  27. As part of an introductory engineering course, we’re taking apart Predator engines. However, I’m not sure if I need a 6 inch puller or an 8 inch puller for a 6.5″ flywheel (which is what the predator seems to come with).

    Is the six inch puller appropriate?

    1. You just need an impact wrench to take the flywheel nut off, and then use a small pry bar and a rubber mallet. Tap the flywheel while using the prybar to put a little leverage on it. Some people break the flywheel loose by just tapping it with a hammer. I have never ever had to use a puller even on old rusty engines.

  28. I disconnected my governor and ran my throttle direct. I did not physically remove the governor from the engine. Will the engine rimfire now that the governor is disconnected? Or do I have to totally remove it? Not sure how it would limit our RPM without being hooked to the throttle.

    1. Mark. Bad idea. If the governor mechanism fails, it will be like a tiny grenade blew up inside the engine and all the bits of metal will cause engine failure. I am not sure what you mean by ‘rimfire’. Also, just remember that the governor is a tiny piece in the performance puzzle.

    2. I am riding mine disconnected but not removed as well. Not having any problems, just tighten something down on the governer lever that connected to your throttle so it doesn’t move and clank with the gear

  29. I just installed the stage 2 performance kit from OMB on my Predator 212cc. New pipe, race carb, 18# springs, breather, and the governor is just disconnected. It will not ripen correctly. It won’t rev up, sputters, dies, etc. Any advice?

    1. Advice? check your valve lash. Physically remove governor. Dont rev past 5500 rpm unless you get a billet rod and flywheel. You dont even need those springs.

  30. I had a friend mess with the screw jet on the side of the carby,and now its dies and idles rough (stock standard motor) how many turns anti clockwise from seated should it be. thanks

    1. ummm there is no screw jet on the side of the carby for the predator 212cc. The only screw that you can adjust on those carbs is a black plastic one, and you adjust it till it idles smooth. If you have a different carb with a brass screw close to the engine side of the intake(idle mixture screw), the standard is about 2 full rotations out from seated. Hope that helps.

      1. I have a 212 cc pred. Engine was going to race it but all the clutches I’ve tried barley move the kart any suggestions these clutches I bought used from a kart shop not sure if it takes too many rpms too turn them or if it’s the engine itself but up on stands it turns the back wheels fine but takes half throttle to turn em

        1. if you got a disc race clutch, they typically engage at the rpms that the predator with governor is limited to (e.g limited to 3600 rpm and clutch engages at 4100 rpm). Might want to call the place you got your clutch from. Honestly, i think it could be either that or your gearing. With smallish tires (15″ or lower) you are usually ok with a 6:1 gear ratio e.g. axle teeth divided by clutch teeth.

  31. I just bought a go kart it has a predator 212 on it. The chain snapped on me there is a chain going from the clutch to a shaft that then has a sprocket that goes to the sprocket on the rear axle. The chain from the clutch to the first sprocket is a 40 the chain from the second sprocket to the rear axle is a 41. Will that cause problems with the chain snapping. Would a torque converter help and what does it do exactly? And I think I can weld a plate on the frame to offset the engine to run one chain from the clutch to the rear axle. I have a lot of questions please help.

  32. I have a 6.5 predator motor on my mini bike i took out govenor and the plastic gears shredded inside the motor and it started dying out n not going so i bought a new motor and took out all parts to the governor completly out then after driving it full out it started dyeing out at top speed on this one too then i read up n said i needed 18# springs to keep it from floating so i did that but its now throwing white smoke from the tail pipe n still at top speed cutting out on me n then dyes completely what do i do or whats am i not doing?? Please!!

    1. Sounds like you are pretty good at ruining your engines. My suggestion would be to call up a go kart race shop and ask them. There are too many variables to mention that could be the cause, and from the sounds of it, you may not even know what to do to get your engine running correctly.

  33. Please suggest a correct gear ratio. I searched on the net and forums and found out that 5:1 gives more top speed but less acceleration than 6:1 but is not capable of carrying weight around 350lbs. so should I opt 6:1? I am using the comet TAV 30 series with 10T driven clutch sprocket and (thinking of)60T sprocket on rear axle with 11″ slick tires. My purpose is a racing gokart not off-roading. The engine is B&S 208cc 9lb.ft@3060rpm with 3/4″ shaft.

    1. Hitesh, 5:1 and 6:1 are both great ratios for 11″ tires and the 30 series torque converter. If you are racing a go kart, then why do you have a torque converter on it? Race karts use disc style centrifugal clutches.

  34. I just bought a predator 212 and I’m about to rejet with a 140/36 combo, I’ve also added a high flow exhaust and intake. My question is my sproket and clutch are from a funkart 5hp do I need to replace these with better ones?
    And should I use full synthetic oil and premium fuel?

    1. premium fuel isnt necessary unless you change your compression ratio (which you have not) any regular pump gas will work, and the higher octane stuff will not make any difference. Synthetic oil will give you a tiny, negligible boost in performance. Clutch, you could do a racing style clutch (disc) or a heavy duty one.

  35. I rebuilt my pred 212 the other day and was riding around and there seems to be a slight loss of power and torque. Also when deaccelerating it seems like it is not engine braking and sounds a bit weird when deaccelerating . My valve lash is set currently to .003, thinking it might be something with valve timing?

  36. This is the picture of the gocar well it looks like it but my back tires are bigger than the picture lol

  37. Today I was riding maybe about 3k rpm or so and I heard a pretty loud bang I wasn’t sure quite what it was so I rode maybe 30 more feet and it did it again so I shut the engine off and stopped. I looked for any visible damage and did not see and. I tried to pull the starter but I couldn’t pull the cord out at all. I drained the oil and took the crank cover off and from what i could see everything was ok. Is it the piston that is seized or what? I can move the piston down with some force, but when it hits the apex and comes back up it only goes up maybe a cm.

    1. Garrett, what you are describing sounds major. There are several possibilities as to what it could be, but you can’t really know until you tear it down. For $120.00, you can buy a 6.5 h.p. Predator from Harbor Freight. It is a Chinese clone of a Honda engine. You won’t be able to fix yours for that, and you can be up and running quickly. Then if you want you can look into the other one when you have the time. This is a shot in the dark, because I don’t know your situation. It’s just what I would do. You may want to take the time to tear it down, and do the research, and buy the parts, and have any necessary machine work done. Anyway best of luck to you.

    2. This happened to a friend of mine on his Predator 212 mini bike. I removed the Flywheel housing and there was a nail nudged between the Flywheel Magnet and the block. I removed the nail and it spun and started right up. Hope this helps you my friend.

  38. I have a Baja Warrior mini bike with a Predator 212. I have read yours and others about performance modification and decided to just modify the air, exhaust, and carb (e-tube 140 and 36 jet). I do not feel I want to disconnect the governor, I just want some more power and torque. As stock I get 22-25mph and with the above modification would expect/hope to get near 30mph. What do you think? Do you think I would notice an improvement with just this modification?

    1. The governor limits your top speed, you will just accelerate faster(more torque), but not go any faster. If you remove governor with those mods, then you can get to that 30 mph range.

      1. I would like to increase rpm from ~3600 (stock limit) to about 4300 to 4500 without removing governor. Can I change spring tension on linkage to achieve that? Also there are two springs in the throttle assembly. Can you explain what each does?

        1. This isn’t possible. The linkage tension only affect the throttle manifold in the carb. The governor literally will limit the Rpms to the stock setting as long as it’s inside. No matter what mods you put on.

    2. More mods won’t get you any more speed unless you remove the governor. Unless you change the sprocket sizes. More mods will just make more power (low end) and acceleration.

    3. Hey why are you only going like 35 mph I have the same thing a Baja warrior with a 212 predator connected to a centrifugal clutch and im going like 55, 60 mph

  39. I have a predator 212 with the modified intake. We are at 4000 foot elevation what do you advise for jet size and emulsion tube? I plan on doing the exhaust as well.


    1. Jetting only starts to matter a bunch above 6000 feet. The higher you go, the less fuel you need as the air density basically allows less oxygen in with the same volume of intake, so you will run rich at high altitude with the same size jet at sea level, so you gotta go with a smaller jet than expected. maybe .032 to .036 range? It really should be based on the power you are making at your target rpm range. You can look up ‘how to read a spark plug’ and get a good idea for it as well as just listening to the engine. If it smokes/bogs down on acceleration, you are probably rich (kind of like you are running it on choke), lean condition can also cause it to bog, but it wont have power and will get hot fast. Id just go with a.036 and see how it feels, you may have to go smaller though based on what you find out with how the engine runs.

      1. Hey buddy do u know anything about cams for the 212cc predator, also i have a torque converter on mine and it runs great I plan to make a mudding cart out of it I wanna take out my governer disconnect my oil sencer putting as high flow air filter and adding a2-3ft pvc pipe so my filter don’t get muddy , putting a performance exhaust also I’m putting a charging coil with the magnetic fly wheel so I can have lights without having to charge a battery I have 28″ atv wheels on it she’ll burn em as it sits but more power is always better haha what cam do u think I should go with and is there anything special I can do to give it more torque ?

  40. Hello I disassembled my new hemi motor .put the mod 2 cam in it. 26 LB springs ARC flywheel thin metal head gasket remove the governor. And that oil sensor. Pipe and air cleaner. rejected the carb . Now when I try to start it . won’t start feels like it has no compression. It has great spark and is getting fuel but it’s like it’s on the wrong stroke! how do I get it back to top dead center . On the compression stroke? I lined up the dogs on the crank and cam. But I think the valves are backwards. How do I fix this ? please help thank you

    1. I figured it out. It was the metal head gasket I put in it ! must’ve not sealed. Put the stock head gasket back in and it had plenty of compression. I found top dead center and it seems to run good.

    2. The thinner head gasket put clearance in the valve train equal to the difference between the two head gaskets. I put a .0010 steel gasket on my Predator 212 in place of the stock .0040 . The engine would not build enough compression until I turned the rocker arm nuts about 1 1/4 turns in. The engine started on the first pull after that.

      1. Daytona, you need to torque head bolts to factory specs and set valve lash to spec for intake and exhaust with a feeler gauge so you get the best performance.

  41. I have a 212cc engine and I think I lost power to my engine once I added a intake my go cart wants to turn off for some reason so I have to accelerate it so it won’t turn off on me

  42. Ok I Have put on a new air filter with the jet that came with it and a new header pipe. I have taken out the Governor on my Predator 212cc engine. My go kart is now really fast and that is what I was going for. It ran great for couple of days I went to start it last night and can not get it started sounds like it is getting spark but will not turn over. Any ideas?

    1. Hmmm is your carb clean? pour a teaspoon of gas in the spark plug hole and see if it starts with throttle wide open. When you remove governor, you gotta make sure that the throttle is manually held open when starting it so it will let air in.

      1. I have tryed everything and still will not start. I guess I will take the side plate off and see if everything is ok inside now I wish I had not ever messed with it. maybe my timeing is off I just do not know. I did not drive it hard be fore it quit.

          1. Adjust idle screw (black plastic one on top) to idle as fast as possible without engaging your clutch. Give it gas only after warming up (run engine a few minutes). make sure intake gaskets are sealing after carb, and that carb has been cleaned.

          2. Finally got the engine started again ran it about a mile and a half engine shut off when I came to a stop. I cant get it started again I am worn out.

    1. a lot. It will increase horsepower and max rpm so you go faster, and have a little more hp. so 7 hp might go up to 8-10, and max speed from lets say 25 might go up to 35 or 40, just depends on what you do and what your gearing is.

  43. Hey, I have removed the governor, blueprinted carb. Jetted to #36 high flow exhaust. I get gas vapor out the carb at full throttle. Any idea what that is caused by?

    1. Hmmm. probably has something to do with timing, valves, flow inertia. If your timing is too far advanced it will cause the air to ‘bounce’ back off of the valve. Valve could not be closing all the way (check valve lash), and with the inertia, your carb doesnt care which way air flows, it just flows from high pressure to low pressure so you might have the wrong size carb opening, wrong size muffler, or a number of things. A blueprinted carb could have an opening that is optimal for lets say 7500 rpm, but you only run it at 400 rpm and you could get that symptom as well. Good luck because I really cant help other than saying that it is a complicated problem :/

  44. I havea prediter engine an im turning it. 4550 an trying yo get more we out up it but im racing stock any advice on how

  45. I have a cl1308 cam it said on card to set timing to 32/34 degrees. It also gave us 2 sets of valve springs. Are we supposed to run them together? How much would it hurt to leave timing stock and pros and cons on the springs if any info? Thank you!!

    1. Some valve springs are dual rate (looks like two sets, but has an inside portion and an outside portion that fit together). If you are just building this engine, you want to take out the inner portion of the spring set for the break in period, then put the inner portion of the spring in after break in is complete. Valve springs are highly dependent on your target RPM and cam, so they are probably the right ones. For break in you want to buy oil specific to break in (aka BREAK IN OIL) brand doesn’t matter as long as it has ZDDP in it to protect the lifters and cam from wearing down before they mate together. To answer your question about leaving timing stock, I would say this: if you want to leave timing stock, do not even put the cam or springs in there. Timing, cam, valve lash settings, and springs ALL work together. If you disregard any of these settings, then your engines performance will suffer.

    1. I have a Pred 212 with no gov, free flow header and uni air intake(filter). I’m Thinking I need a new clutch, as I am going above about 3.6k rpm at times. I’m not sure on what one to get. What do you recommend?

      1. any racing clutch will work, noram cheetah, bully etc as long as it is a ‘racing’ clutch it will rev as high as you want it. Will cost $100-$350 depending on quality of clutch but they will all work.

  46. Need help, I’ve drilled holes on the stock airfilter box, changed the exhaust to a 1 inch pipe. After those mods my predator 212cc takes a while for it to start.

    1. the governor was removed? Governor holds the throttle open so if you remove it, you gotta put on choke and manually hold governor open and it should start right up. If its already warm, you start with no choke.

    1. the breather tube out of the halve cover should just vent to atmosphere. The tube from the tank can be capped, but its not necessary as it actually has a check valve in it.

  47. I have read just about every comment on this thread. Highly educational. Glad to know the answers to all these common issues. Great Kart rebuild site!!

  48. I just upgraded the intake, exhaust, and carb jet. I’m quickly reaching the motors peak because of these recent upgrades. What should be my next upgrade? Removing the governor, obviously. But after that it seems I would need to upgrade the other components on the motor. What would those be?

  49. i have not made this yet but i am gonna build it now because the engine is on sale for 99.99 on harborfreight.com but if i buy the engine the kit and the steel is that everythig i need

    1. It will run lean, overheat your engine, and have poor performance at best. At worst, you can seize your engine. Let me ask you a question: why bother with an intake and exhaust if you aren’t going to jet it correctly? Might as well keep it stock if you do that.

  50. Hi again, normally for the stock 6.5 hp engine I would need a 30 series torque converter, but if I add all of these performance parts will I need a bigger torque converter since it increases the hp?

  51. question I’m running the 212 predator motor with a header mod drilled out intake runs fine just having hard trouble starting really hard to pull then jerks back at some points what could be the problem

    1. Valve lash set too wide (doesn’t open compression release) or a sheared flywheel key (timing messed up). Did you ever mess with the head, flywheel, or put in a cam without a compression release?

  52. I bought a upgrade kit to install on my predator 212cc motor. I’m not sure how to install most of parts. My biggest question is how i install the walbro fuel pump. Do i just use the hole in the OHV cover to the vacuum side of the pump or what?

    1. If you plan on keeping the stock gas tank on the engine, there is no need for a pulse pump like that. The only reason you need that is if you install a remote gas tank below the height of the carb. The valve cover does need what is called a ‘pulse fitting’. The hole that is already in the cover is to vent to a catch can with performance intake already there. There are plenty of places to find out where and how to install a pulse fitting based on your valve cover (hemi/non-hemi) so you just need to do a little searching on google.

  53. i plan on doing the intake, re-jet & exhaust and maybee hi-comp head….this is just a predator powered fun kart…question is, at what point is a better centrifugal clutch needed & what do you recommend???

  54. I have several ?s i am running a box stock predator class we are allowed to remove the gas tank an replace with a topplate an fuelpump we are allowed to remove the govenor and low senser switch We have to run the factory air box and factory exhaust the engines are goin to be sealed so my ? i know i cant change the valve springs because they will tech those what can i do to just be at the limit of passin tech an get all the hp i cn get outta it any ideals or theorys eould be greatly appreciated

    1. LOL!!! Whell I would say, follow the rules or risk getting banned. Can you run a cam? Can you mill the head? can you deck the block? can you index the spark plug? Can you install a longer plug for higher compression? Can you run light oil? Can you bore out the cylinder for a slightly larger displacement and slightly larger piston? Can you get a slightly longer rod for increased compression? Can you advance timing for your target rpm? Can you get a billet flywheel? Can you jet for your target RPM? Can you get a bored out carburetor? Can you port and polish? CAn you install different ratio rockers? Can you install roller rockers? can you get higher nose pressure springs that are still legal? Can you install a gx160 head for higher compression? Can you taper the exhaust pipe to mate perfectly with the exhaust port? can you polish the exhaust tubing interior for optimal flow? Can you get chrome-moly push rods? Can you install file to fit rings sized to your target max RPM?

      Other basic stuff that is LEGAL would be to properly break in your engine, lap your valves, and ensure proper valve lash.

      Also, tires and optimal GEARING are going to get you far, and probably make the biggest difference besides the engine. Crap tires or incorrect gearing can ruin you in a race. If the rules allow it, get a disc clutch (e.g. cheetah, bully) instead of a centrifugal clutch, and set engagement at peak HP rpms. Make sure your alignment is good, and is done perfectly for the track you will be racing on (e.g. oval vs other. Bearings should be in excellent shape too.

      1. I have a predator motor and everything on it is stock. I took the governor out and the oil sensor. It also has the performance exhaust header on it already. I want to take the gas tank off the top of the motor and put the top plate with the fuel filter on top of the motor. One line on the filter runs to the tank, the other one goes to the carb, but I think the other one is supposed to go to the OHV cover. Do I have to tap a hole and put a spout on there to run the line? Also I want to know how much hp it will have after I replace the stock flywheel, use longer rods and all that other performance stuff.

        1. Colton, you don’t need to put a pump on the motor with the gas tank setup that way. The choice is up to you though, and yes you would need to run the fuel pump off the crankcase pressure. If it were me, I’d just leave the tank on it and get the performance intake and re-jet the carb. You can expect about 8-10 hp (vs 6.5 hp stock) with those upgrades. Do not get a longer connecting rod, just get stock unless you plan on getting a performance piston that calls for a different length billet rod.

  55. I have removed the governor. And the oil sensor on my motor. What do I do with the on off switch? Will it run with it disconnected?

    1. the yellow wire (assuming you have a honda clone or predator) that goes from he low oil switch that comes out of the block has a bullet connector to another yellow wire. All you have to do is unplug the yellow wires and it will prevent the engine from dying around corners. The kill switch will still function this way.

  56. I’m a little nervous as to remove the governor, I’ve had past adults in my life telling me that removing it is a bad idea, are there any precautions I should take? What risks do I run (besides blowing up my engine)

    1. Also, if I’m removing it from a predator, which already has a seperate throttle system, would I need to do anything to ensure that the throttle would still work

      1. yeah man, removing the governor is a big deal. If you over rev you could break the connecting rod or shatter the flywheel. Connecting rod is more likely to go, and it would punch a hole in the block if it went. If you stay under 5000 rpms, this probably wont happen, and valve float will probably occur before you reach rpms that could break the connecting rod or flywheel (happens around 6000+ RPM, but is not a figure to say anything less than 6k is good, which it is NOT). Don’t put in heavy springs unless you get a billet connecting rod and billet flywheel, then the motor will be good for a much higher RPM.

    1. To do 10k you will probably need a stroker kit from arc. a Big mikuni carb. Roller rockers and a high lift cam. You will also need some cnc ported ports in your head. It might make it.

  57. I have the predator hemi with 26lb springs f275 cam ss valves 1 to 2 rockers head milled 050 will this set up be ok for valve to piston clearance please help dont wont to blow it up. Thanks

    1. Check your cam card. A cam with a high lift accomplishes the same thing as rockers – they both lift the valves HIGHER, allowing air and exhaust to flow more freely through the head. This is further complicated with TIMING, and clearance with the head being milled… Here is what CAN go wrong 1) higher valve lift may cause springs to bind – you don’t necessarily need super heavy springs, just springs that are good enough for your target RPM, springs rob hp, but let you rev higher. Check spring specs vs total lift height of valve. You may need to do some additional work with creating a pocket and installing a retainer so the springs don’t bottom out. 2) higher valve lift in conjunction with a longer duration cam, and advanced timing may cause valves to contact piston (unlikely) but it needs to be checked. You need to figure out DURATION of the cam to make sure the valves are closing in time. You can do another check by putting play dough in the head, and rotating everything. The valves will leave an imprint on the play-dough and you can see if it is thick enough. You will need to call a reputable race shop and ask them, or do some serious investigation looking at tables to make sure everything works out alright. Please, make sure you put on a billet flywheel and billet connecting rod. Because you have heavy springs in there, you don’t want the engine to over rev and grenade the connecting rod and or flywheel.

  58. I’m sitting here reading the comments and thinking about porting and polishing, cam, larger jet in the carb, new flywheel, and connecting rod hooking up a tachometer, and oil temp gauge. With the cam I would need the stiffer springs, and while it’s apart, might as well lose the governor. Then the man said, if you are going to do that much, you might as well go with a two cycle that was designed for that. I thought we were staying with a common theme here. Home built Go Cart with a Predator engine. That combination is really cool because it allows just about everyone to get a Go Cart. Not just any Go Cart, but one that is a good cart , with a new engine. The fact that you put it together yourself is just icing on the cake. The design of this cart, I think is excellent, so it’s going to be that and the Predator.

  59. I have upgraded my predictor motor with the header pipe,intake,carb. When I start it it smells like something is burning . Any clues what it could be

    1. well, engines burn gas to run, so that might be it 🙂 What about jetting, did you rejet? After you run your engine for a little bit, check the spark plug. Is it wet? Dry? Black? White? Brown? Any colored smoke coming out of the exhaust after it warms up and you have the choke off?

  60. Ok so I upgraded my 212cc predator and put an air filter adapter with air filter . Where do the lines from the top of the gas tank and the other line from the valve cover go? I’m trying to find out what to do with both of them. Plz help. (And it’s also a he might if that has anything to do with it)

    1. the line from the gas tank is just a vent that the EPA requires. It has a one way check valve in it, so you don’t have to do anything with the line from the tank, just don’t plug it. The line from the valve cover is also one of those emission reducing lines so it originally vented back to the airbox. Well, you dont really need that to vent to the airbox, so it can vent to atmosphere. Some people attach a hose clamp and small air filter or fuel filter on the vent to keep dirt from getting in the vent. Some people just rotate it and let it vent downward.

  61. I have a non hemi predator 212 with a wind pma on it that runs 24 hrs. I have carb problems as the engine doesn’t run very smooth. Any recommendations to what I can do to this for fuel economy and smoothness and longevity.

    1. hmmm, i would say best practices would be to remove the air filter and pre filter and get a new one, wash the pre filter and make sure you change oil and air filter according to run time in the operation manual. The carb would need to be cleaned. If you want the engine to run best in the long term, you don’t want to remove the governor, just keep it all stock and maintain it according to the users manual. Syntheitic 10w30 oil would probably be the best in above freezing temps, and 5w30 in below freezing.

  62. Hi,
    Great thread! I’ve read that if you remove the governor that the flywheel should be replaced with a billet one. Apparently, at higher rpm the stock flywheel can shatter. I’ve never seen this personally. Do you agree? I’m not racing my kart. It’s just for fun but I want it to be safe.

    1. Mike, you should buy a tachometer and make sure that you never exceed 5500 RPMS with the stock flywheel. Once you start exceeding 6000 rpms you will need to get a billet connecting rod and a billet flywheel. The thing that prevents exceeding 6K rpms is what is called ‘valve float’ – valves stop seating because the valve springs can’t fully close them before the next cycle. This acts as a secondary governor to keep the engine from failing. You can get a cheap tachometer from ebay and monitor your RPM’s to be safe. As a disclaimer, you are doing this at your own risk and the liability is completely yours for any engine modification other than stock. Whatever you do, NEVER replace the valve springs without replacing the connecting stock rod and stock flywheel with billet aluminum ones at the same time.

  63. If you have the high flow header, the high flow intake, and re-jetted carb, what kind or power should you expect? Is 8-10 HP and 10-12 ft-lbs a reasonable assumption?

        1. If you want it to be stock appearing, you don’t mod it 🙂 Stock appearing usually refers to springs, which are usually meant to look stock, but may be illegal to race with, unless your particular set of rules allow ‘stock appearing’ mods.

      1. It is best to change out the emulsion tube when changing out the jet, but not required. The emulsion tube change just allows for a stronger fuel signal in the carb.

    1. The oil sensor removal is not required. Most people just disconnect the yellow wire coming out of the low oil shutoff. It has a simple bullet connector that you just separate.

  64. I live in the suberbs with no-fun parents and neighbors; Adding a header will produce too much noise. Is it possible to skip the header, and just go for the jet and intake mods? Or if someone knows of of high performance header, that also muffles noise, that would be very appreciated. Thanks!

    1. yeah you could skip the header, and do intake/jet mods.

      The high performance headers also have the option of putting a stinger style performance exhaust muffler on them. If you click on the link, you can scroll down to see the other items that are related to go kart performance exhaust systems and get the stinger muffler (from what I am aware of, it just clamps onto the exhaust with a hose clamp.

  65. I have hemi 212 what you recomend to get 15hp,thats what I need to get in the air with a paramotor, If get 6500 rpm with 2to1 reducción to the propeller I will be fine
    Thanks you.

    1. Intake, exhaust, governor remove, rejet.

      Arc billet flywheel w/adjustable timing advanced to ? 8 degrees ?, arc billet connecting rod and bearings.

      New valve springs with higher lb rating than stock. New valves meant for racing. New rockers meant for racing. Walboro fuel pump. Direct throttle linkage. Racing cam.

      Also, to monitor your engines performance, thermostat and tachometer. If the engine gets too hot you could warp the valves and grenade the engine.

      If it were me personally, I’d get a high performance 2 stroke meant for this stuff, as your life literally depends on it.

      1. Thank you very much for you advaice, i being flying for a month without any problema pleny of power.

Leave a Reply

Your email address will not be published. Required fields are marked *

Free Go Kart Plans, Restorations, and Maintenance