Go Kart Engine Overview From Cheap to Best

There are plenty of go kart engines out there.  Choosing the best one will be a balance of cost and reliability. After reading this list, you will be more informed as to which one you should get.

Maintenance

  • Oil: You should change the oil about ever 20 hours, or once a year. Most go kart engines should take 5w30 or 10w30 ‘energy conserving’ oil. I use fully synthetic  on mine.
  • Air Filter: The air filter should be changed when its loaded up with dirt, or as often as your oil. Most filters come with a foam pre-filter, which can be cleaned out.
  • Gas: Most industrial engines required regular unleaded fuel. Most fuel currently contains 10% ethanol. Gas will turn to varnish over time, which will gum up your fuel delivery system. Adding a fuel stabilizer (available at any hardware or automotive store) will usually let you store your kart with old gas in it for a year with no problems.
  • Clean: If your engine is covered in grease, you can spray on an engine degreaser, let it soak, then wash it down with a hose. If your engine is not running, chances are you have a dirty carb, and you should clean it out.

Cheap Go Kart Engines

There’s cheap, and then there’s ‘cheap’.

The only contender  for the go kart engine that is cheap, but not built cheaply is the predator 212cc engine. No engine comes close to its usefulness, and its actually reliable (see below).

Best Go Kart Engine

The best go kart engine for kids should sit right around 5-7 hp, have a 3/4″ shaft, and fit a centrifugal clutch or 30 series torque converter, and has a standard bolt pattern for easy mounting.

Honda GX200 the king. The Honda GX series engines  are built well, last long, but are a little expensive. There is a large market for this engine in racing, and with performance parts. The only way you can beat the honda gx series engine, is to make a copy of it in china, and sell it cheap, and that is what the box stock project clone engine is. Clone engines are arguably the best engine out there for go kart racers as they have their own class for racing. You can click here to see which the 6.5 hp engine the honda clones are copied from.

Briggs 5 hp Flathead is still out there. It was the king, but still commands a large presence. Many spare go kart engine parts, and performance parts are available for this classic engine. The newer OHV style engines outperform this engine. Briggs also has a niche market for go kart racing OHV engines, which are pretty pricey.

Subaru EX17 I would put this up there with Honda as far as reliability goes, and they have some impressive engineering going on. However, steer clear of any Subaru industrial engine for a go kart. Unfortunately, replacement parts are about 500% higher than they should be (e.g. a replacement carburetor that should cost $15-$20  is $100. The performance part market for Subaru engines is almost non existent. If you are going to get a Subaru, stick with the car, not the small engine.

The Infamous Harbor Freight Predator 212cc engine is the best go kart engine because it is copied for the most part from a Honda GX 200 series engine, but it sells for much less. A win-win for the consumer. So if you have an old go kart with a junk engine on it, you can spend $40-$80 in parts to fix up, or buy a new predator 212cc engine for $100 and perform a simple engine swap, the choice is clear.  Race classes use this engine specifically, and the go kart performance part market is up to its eyeballs in predator 212cc performance parts, such as the high flow intake and air filter, and the bolt on performance header pipe. Many go karts have been fixed up to have this reliable, cheap engine, which is why it is one of the best go kart engines used today. If you want to buy a predator engine, you can usually get a coupon and order one online from http://www.harborfreight.com for around $100.

The Big Boys

These engines should have a 1″ shaft, range from 8-13 hp, and utilize the 40 series torque converter.

Honda GX340 GX390 11-13 hp I personally have the 11 and 13 (340 and 390) versions, and they are a blast to drive. Plan on going about 40 mph with plenty of torque on these guys.

Briggs Vanguard 10, 13 hp I haven’t seen many of these around, but they are work horses, just like the Honda GX series engines.

Predator 13 hp 420 cc: A few more cc’s and a lot less expensive than the briggs and honda counterparts, this engine is great.

The Biggest Boys

These engines are too big for any go kart, are meant for industrial grade work, and push beyond the limits of any transmission meant for a go kart. That’s why we like them, right? These come standard with key-start, and have plenty of amps to run off-road lights. These are perfect for a mini buggy type off road vehicle, or performance golf cart.

Honda V-Twin The GX630 and GX690 range from 20 to 22 hp. Older versions include 610, 620, and 670.  I currently own a gx620, which I will be installing on a mini buggy.

Briggs Vanguard V-Twin The 16 hp vanguard is the smallest v-twin, and is really the only v-twin that is safe to use with the 40 series torque converter (which is rated to 18 hp) and the Comet FNR gearbox (which is rated to 16 hp). The briggs vanguard v-twins range all the way up to 35 hp!

22 HP (670cc) V-Twin Horizontal Shaft Gas Engine EPA The newest addition to the V-Twin pool, which is a 22 hp, 670CC engine. True to its history, the predator v-twin 670cc 22 hp engine is cheaper than the industrial honda and briggs v-twin engines, and looks just about as reliable.

This is part of the go kart maintenance section.

Did I miss anything? Please comment as I am constantly updating this website.

158 thoughts on “Go Kart Engine Overview From Cheap to Best”

  1. Looking at replacing a off shore 150cc motor in a gokart with a horizontal 196cc (6.5 dewalt) not sure if it will work? Any suggestions? Dewalt motor is new in box

    1. gearing will be different, motor mount etc. typically the 150cc engines are a GY6 engine or knock off that has different internal gearing, and a smaller axle sprocket. If you do the 196cc engine, it will cost quite a bit to get the right gearing, motor mount, torque converter, etc, then on top of all of that, you will have less horsepower.

  2. Love your site! Thanks for all the detail you give. Can’t wait for the next project.
    Do you have any suggestions for Electric Motors?

  3. Hello. I just removed a busted 124cc kinroad from a go kart. I replaced with a 208cc Briggs and Stratton I got cheaply. I just want to go straight to the axle. I loose reverse and that’s fine. The Briggs has a 10 tooth centrifugal clutch. What size sprocket should I use on the rear? The old sprocket was a 37T and the engine can’t move the kart. Also is there a slide type carb that will fit my Briggs? So I can screw in the old throttle cable and avoid fabricating a throttle linkage? Thank you so much

    1. if the briggs has a 10t cent clutch, you want a 6:1 ratio (or higher ratio preferably) with tires that do not exceed 15″ in diameter. If the tires are bigger than that, you will need to do compound gear reduction, or use a torque converter.

      1. there is no current reverse gearbox that you can plug and play for a go kart engine above 8 hp. The comet FNR gearbox is out of stock and out of production IIRC, which was good up to 16 hp. The only other alternatives involve taking an ATV transmission and using that for your driven unit to attach to, then adapting it to your needs. If you hop on ebay, you can search “polaris gearbox” or polaris transmission to get an idea of what is out there.

  4. I also am modifying my Johnson kart into a bad little road kart what is a common or good rear axle size on them by chance I was thinking 34″-36″ does that sound about right

  5. You seem to know a lot about karts I recently bought one with the qmj157 gy6 on it and I am having trouble finding the right parts for it I need transmission bearings I think I can open it up and put all the gears in right and ride it for an hour or two then they jump outta place and I have to limp it back any ideas on what it is and where to get it I’ve never messed with these karts new in the game

    1. 99% of the “150cc chinese buggies” are using either a gy6 or exact clone of a gy6 engine. IIRC these engines are all pretty much the same. Some have a short trans, some have a long trans.

  6. Kartfab, excellent all around.

    I have Kinroad Sahara 150cc. Want to replace engine. Which predator do you recommend? 212cc, 301cc, or 420cc. Any other necessary gearbox or other parts you recommend. Thanks

    1. if you replace a 150cc gy6 or similar engine, you will need to 1) fabricate a motor mount 2)adapt or replace reverse. chinese reverse kits are good up to 8 hp, and the comet FNR gearbox is good up to 16 hp 3) figure out how to adapt linkages to the gearbox 3) change gearing for the go kart, typically 10 tooth jackshaft sprocket and 60t axle sprocket.

  7. I purchased my son a Trailmaster Mini XRX. I am just wanting to see what all parts will I need to replace the factory engine with a 6.5hp 212cc Predator Engine. I was looking at repairing the factory engine but the parts are more expensive then a whole new engine. Thanks for your help

    1. Ricky, the factory engine looks like a clone of the honda gx160, so swapping it out for a preadator 212cc will require you to basically pull out the four mounting bolts, and then disconnect the throttle cable, then bolt the predator on and connect the throttle cable. You will probably have to ditch that little muffler guard. The engine swaps are extremely easy to do.

      1. Thanks for that information. I am a mechanic but I wanted to make sure that the engine mount that is on our kart would work with the Predator. So all the parts that are on the current engine such as the clutch will also work with the Predator?

  8. I have a Kandi buggy and I am wanting it to go faster and have more torque… I am new to all of this so what do I need to buy to achieve: more torque and higher speed? The model number of the buggy is: KD-150GKM-2
    Thank you for all your help

      1. Thank you for the quick response… Yes it does have the gy6 motor… Would it be better to just change motors? If so, what motor and what do I need to do? I just don’t know if that upgrade kit will be enough power, I was thinking a 200+cc motor, but I could just be thinking too much…

  9. I purchased a gx390 thunder kart on a suzuka chassis.
    Centrifugal clutch engages a soon as engine is cranked and started.
    Need to raise the rear wheels so it doesn’t take off plus it makes it easier to start.
    I bring the idle screw right out its stalls.
    Even stalls when it’s 1 turn or 2 turns in but 2.5 turns will keep it running however clutch engages and wheels will spin.
    There is 13t on front sprocket I forgot to count rear sprocket so that makes no help.
    What do you suggest? Thanks for your time

    1. check to see if your clutch is seized internally, or if the spring is shot. The spring when unwound should lay flat. My guess is that it seized up, or that the spring is toast.

  10. Good Day Kart Fab- Any ideas as to how to change and/or adapt a flared crank shaft to a straight one? I’ve have a Briggs 14hp V-Twin Vanguard that I want to attach a Torque-Converter to. The TC only has straight shaft drives. Briggs won’t suggest a compatible crank shaft and I haven’t located an adapter sleeve. Is my only option milling the crank shaft down? Even the most far-fetched advise would be helpful. Later. -Tony

      1. From what I have heard and have been told the tapered shafts were built for only what it was originally on. I’m sure you could change the crank shaft. But would it be worth the trouble?

  11. Hey, I bought my daughters a used Carter TrailRunner go-cart with the Tecumseh 6.5 hp motor, which uses a belt/clutch to power it and on the other side a chain and sprocket to put the power to the wheels. It does have a Comet 20 series clutch. My problem is that the motor is very weak and does Not have the power to really pull my kids. And I’ve done some research and haven’t really heard anything good about those engines. What engine can I replace it with, without having to make or build new brackets and stuff, but still be able to keep the Comet torque box(maybe just upgrade it to the 30 series)?!?!?! I really don’t have the money or the time to do a really big swap and go all out but I do want my girls to be able to have a blast and love it. Any info, and all info will be GREATLY appreciated, and thanks.

    1. Predator 212cc engine is the cheapest most reliable swap for that. It has the same mounting pattern and crankshaft position, so you dont have to modify anything. The pto shaft is slightly shorter, but nothing a few spacers cant handle. Its night and day performance change. Might want to get a new belt and clean the torque converter for the swap too.

  12. Hello,
    My son and I have a question. We purchased the springer upgrade in the kit from Go Power Sports. The build plans show 1″ from the top of the front axle to the top of the spindle, but the springer spindle bracket is taller. Not sure if you have the measurement from the bottom of the standard spindle to the bottom of the axle, or possibly the measurement on the top for the springer spindle bracket.

    Thanks,

    Aaron and Conner Green

    1. The springer suspension was added by go power sports long after the plans. I’d say that you would be fine welding 1″ from the bottom of the bracket. E.g. 1″ from the bottom of bracket to bottom of front axle.

  13. What type of torque converter would you recommend for the predator 22 hp (670cc) vtwin engine the 40 series TAV is only good up to 18 hp and it’s expensive to buy as a component to just burn out.

      1. I’m trying to make a mini buggy type cart with 4×4 for only off-road use w/ lights and and I wanted the additional horsepower to supply enough torque to the 4 wheels to ensure it does not get stuck so I figured the 22 hp vtwin would do the job and thanks for the info I’ll look into the comet 780 series for my purpose.

    1. I’m installing a predator 420cc and 40 series torque converter in a Kinroad Sahara 150. considering a comet forward/ reverse gearbox. what drive gear and sprocket combo would you recommend?

  14. im running a 8hp predator 301cc cleary its an odd ball because it seems no one else is running them..ordered what i thought was the 40 series TAV ,my fault, was 30 series 1inch crank kit with back plate.. am i going to burn this up? or is it possible to take the drive and driven off and order the 40 series drive and driven and install back on my TAV back plate? know that the TAV came with back plate(whole assembly).

    1. Adam, not sure on clearance for back plate, but the 30 series is rated for up to 8 hp. Some people have had to cut part of the oil plug handle off for the backplate to be 100% secure. If it were me, id keep the 30 series. You CANNOT put the 40 series drive and driven on a 30 series backplate as the center to center distance is not at a compatible distance for belts (they are too close together).

    1. the problem is that you need a horizontal shaft engine, and all mower engines are vertical. A lot of people buy a lawn tractor, swap out pulleys, and put a centrifugal clutch/pulley on output shaft. Good luck.

    2. My dad and I built a go-kart with a vertical shaft engine when I was a kid. From the engine was a belt that twisted 90 degrees. It then went to a shaft with a pulley on one side and a standard go-kart clutch on the other. From the clutch, the chain went to the sprocket on the tire. It worked OK but I wouldn’t waste my time building that now when you can get a HF engine for $100.

  15. I have a kandy b90 kart with all electronic everything, can I replace the motor that is bad with the predator motor and do away with the electronics

    1. It’s not that simple. You will lose reverse, will have to buy a 30 series torque converter, and fabricate an engine mount. Additionally, you will have to check gearing, and probably re-gear it. Or, you could fix or replace the existing engine, which is probably the better choice.

  16. Planning on replacing a Kawasaki Mule Diesel, with a Predator 22 h.p. (Kaw twisted a rod due to hydraulic, punched a hole in the block when she blew) Going to order a “plate kit” that a guy makes up in Kentucky, and mount the predator. Just wanted to know if you’ve heard of that conversion, what problems that you might be aware of, and to prepare for??

  17. I jist bought a kart with hand controlls and a 5hp tecumseh power sport motor. The pull start on it is broke how do i know what to replace it with?

  18. I have a manco xtk 710e I’d like to put a bigger engine on it which do you recommend that will line up with Subaru Robin 10hp?

  19. I have a Honda GX390 would it be better to Jack shaft it with a belt torque converter or direct drive it with a chain torque converter I am mounting the Honda GX390 to a older style Rattler go kart it’s got some weight to it

    1. torque converter is best for climbing hills, clutch is only good on flat to moderately flat. Torque converter with the same gearing provides much faster accelleration and a slightly higher top speed. Clutch may burn up if you have tires greater than 15″

      1. can i bolt a big block predator to my engine mount on my race go kart? the engine mount has the ones the 212 isbolted up to, and then a hole on each side of the motor mount, wider then where the 212 bolts up to

    2. I have a kart that’s got some bigger wheels on it with a 212cc predator on it And the normal clutches won’t cut it I’m ordering a torque converter off the web and I suggest that u do the same from everything over read unless your building a kart for the track only and willing to spend 400+ on a racing clutch the torque converter is the way to go

  20. I just recently got a briggs and stratton rototiller engine and its working really well but I can’t figure out if its a good fit cause it’s only 4hp. Any thoughts ?

  21. I was wondering if you have any experience with comet’s 94 duster torque converter? I have always wanted to get my hands on one. I recently found mfssupply.com has them again, and I need to order one for my build. Comet’s torque converters can take a heck of a beating (my 40 series is still kicking 😉 ), and the 94 looks sweet on paper! If I remember right, it will accept up to a 1 1/8″ belt, and the low ratio is 3.48:1, with a .78:1 high ratio! Thanks, and keep up the great work!

      1. Thanks! Yea I don’t remember why I dismissed the 780 when I was looking?! The 780 will accept up to a 1 1/4″ belt according to Vegas carts, and they are saying it can handle 20+ hp, which is a bit more than comet recommended, if I remember correctly. The gear ratios are even better than the 94 though, too! 3.71 low and .69 high!! The tall OD ratio would really reign in a low final drive ratio, but looks like I’d have to be careful not to gear too high. That’s the beauty of sprockets though. Lol.

  22. Good evening, everyone, and let me say thank you to kartfab for the cool website!
    While reading through the question and answer section here, I see there is a lot of confusion over gear ratios, and more importantly, how to apply proper gear ratios. (My hat’s off to kartfab for trying to explain this)
    Ok, so to keep things simple, I want to explain how we determine gear ratio when using sprockets, compound gearing (jack-shaft) and torque converter drive systems as these drives are used on go karts.
    To start, we need the basic fundamentals of gearing with sprockets. In our drive system, we have “drive” sprockets and “driven” sprockets. For our application, the drive sprocket will always be smaller, and have fewer teeth than the driven sprocket. The relationship of driven teeth divided by drive teeth is called ratio. For example, an axle sprocket having 60 teeth is being driven by a sprocket with 10 teeth. Here, the gear ratio is 6:1.
    Now, a NUMERICALLY HIGHER ratio denotes a LOWER gear ratio, while a NUMERICALLY LOWER ratio denotes a HIGHER gear ratio.
    Lower ratios can provide more torque for acceleration, pulling, or climbing hills, but at the expense of top speed.
    Higher gear ratios trade acceleration and torque for higher speeds.
    So now that you can calculate the ratio of a drive and driven sprocket, and understand what the resulting ratio will do, what do you do when you have a jack-shaft on your cart, and now there are 4 sprockets? This is a form of compound gearing, and jack -shafts are commonly used to alleviate drive system space constraints, and to change alignment of the drive. Perhaps one of the best advantages of a jack -shaft is to allow gear ratios to be “dialed in” to that sweet spot. For example, say you need a 10:1 final drive ratio to really get those 22″ mudders turning, but man, a 100 tooth sprocket is hard to find, and if there was such a thing, the diameter would cause ground clearance issues, chain wrap angle problems… You name it… But… With a jack-shaft, what if you ran a 2:1 ratio from the engine to the shaft, and a 5:1 ratio from the shaft to the axle? Now you have a 10:1 ratio, excellent clearance, proper chain wrap angles and chain speeds, and a much stronger and reliable drive system! And this is how the over-all ratio is determined. Find the ratio of the first set of sprockets. Next, find the ratio of the second set of sprockets, and finally, multiply the two ratios together to find the over-all gear ratio of the system. After all, isn’t that what we are after? Making torque multiply!
    Whew, sorry for the long post, but hopefully this will help to clarify some of the confusion in figuring out gear ratios!

  23. Ok so I just got this Chinese buggy 2 seater and I want to take it off road (trails,medium hills,) it has no drivetrain. I want neutral and reverse but also want it to get out of its own way . What would you recommend for my situation. I’m looking at the preditor 420cc with the 40 tourque converter and comet reverse. Would this be powerful enough to do what I want thanks

    1. might want to put original parts in it. However, the 420 etc will work just fine. If you go much higher in horsepower, you will not be able to use the comet reverse gearbox as it is rated for 16 hp.

  24. Hellos I want to put a v twin engine on a buggy I am building from components I got from a recked side by side, will a v twin engine blow out its oil if corner too hard or if I get it on an angel for any reason? It’s mainly the cornering I’m worried about as I have seen one do it on YouTube I think it was a predator 670. Thanks

  25. My son has a Manco fox phantom 2 seater go kart with a 10Hp 265cc Subaru engine. He wants to put a 22Hp engine in it. As I’m fairly new to all of this I would like to know if this is possible, and if so what it’s going to take to make it happen? Any advice you might be able to give on this would greatly appreciated. Thank you.

    1. yes it is possible, but not safe. The first thing I would do is take off the existing engine (4 bolts) and measure the bolt pattern on the mounting plate of the go kart. Next, measure the bolt dimensions (found in users manual of 22 hp predator). If they match up, you can pull it off. If they dont, you need to get a new motor mount fabricated.

      If you have a manco and it has a 10hp engine on it, it likely has a 40 series torque converter, which is only rated to 18 hp. You ‘can’ put it on the 22 hp, but it may end up wearing out prematurely, and at the very least, wearing out belts faster than normal.

      1. Thank you for your prompt response. Safety is our number 1 goal if we decide we want to move forward. I’m not against doing whatever fabrication would need to be done as I’ve worked much of my life in the welding and fabrication trade. Are there any alternatives to using the 40 series torque converter to compensate for the extra Hp or would it be in our better interest to look into an 18Hp engine?

  26. I’m planning on building a smallish ATV. 2wd only but I plan on using it for pulling a small portable fish house (pop-up style), with a 20lb propane cylinder and heater, plus fishing gear. With just myself on it, it’ll be close to 265lbs and with what I mentioned, it’ll be pulling close to 75lbs but on snow/ice. I’m trying to decide on the 301cc Predator and 212 Predator and whether or not i should get a torque converter. I know the 40 series is more than twice as much as the 30. I will be going off road on some trails but will be avoiding as much mud as possible.

    Going to use 14″-16″ tires and gearing with a 10 tooth and 72 tooth, since nothing that I have found goes higher for 420 chain, unless I do a jackshaft to get a lower gear ratio. Would a 301cc serve better than a 212cc and should I try to get a torque converter or if I gear low enough 8:1 or 9:1 and use like an Inferno 10 tooth clutch, would that suffice?

  27. I apologize in advance for the noob questions. I can/have taken my Harley completely apart and took it from a 103 to a 110, but I don’t know anything about go karts.

    I bought my 14year old daughter a Chinese dong fang Jaguar go kart that came with a 169cc motor (electric start, forward, neutral and reverse). If gets up to about 30mph (according to its gauge) on the street but it doesn’t seem to have much torque. I’m worried that when we get it off road on trails it won’t be able to get up any hills and I’d like it to be just a bit quicker since its big enough for adults to play on. It will never keep up with my RZR but that’s not what it’s for.

    I’ve been searching for performance upgrade options I might consider for the stock setup but haven’t seen much and instead keep seeing posts about predator motors as replacements. I saw the 212, 301, 420 and 670 motors in a local store today ranging from about $90 – $350. The 420 and 670 even had electric start.

    So my questions are:
    1) What might I do to the Chinese motor to pep it up and help it up hills?
    2) If I wanted to consider the 420 or 670 as full replacements what do I need to use for the complete drive train (clutching, sprockets, etc.) to make a safe reliable machine that continues to have electric start, forward, neutral and reverse?

    I can do the work but I have no idea what parts to get/use. If you can map out a parts list and design I’ll make it happen.

    Thank you!

    1. whew thats a big request. Ok so i would just re-gear if you are worried about torque. On the output shaft of the transmission there is a small sprocket on it. I would check to see if you could get a sprocket with fewer teeth on output, or a sprocket with more teeth on axle sprocket. It will be a little slower, but have more torque.

      Im afraid if you upgrade to the 420 or 670, the drivetrain wont handle the extra hp. It may be possible for use a predator, but you lose electric start. Might want to try a honda gx200 with electric start (only if old and new engines are compatible with mounting etc).

  28. Do You know/heard or new star technology go karts?

    i have a nst 250cc dune buggy. and thinking about putting that 670cc predadtor motor on it , instead of messing with existing motor. this dune buggy has a gear box on it. if i mount the 670 predator on it and connect the shaft from the motor to the drive shaft into the gear box.. …. (gear box is attached to chain and sprocket) will that work instead of using a torque converter and clutch ?

    1. I put a 212cc predator with a turbocharger on my gokart.
      How do you hook up a boost gauge to a turbo??

  29. Hey hows it going i am starting my project it is a joyner 250cc frame 2 seater kind looks like a mini buggy
    but has no engine i am thinking about the 440cc 18 hp duromax but im wondering what kind of sprokett im going to need to pull my joyner to good speed also do i need another clutch because i do not want to burn my clutch ? what are your thoughts ? is it hard to find performance parts for the duromax engine ? i would greatly apprciate your help thank you very much looking forward for your professional help

    1. Also what size of tires will i need for the best ride or will that not matter sorry for all the question is my first project so would lie to hear your thoughts thanks again

  30. My project is a Chinese two seater dune buggy originally had GY6 150 with Ford neutral in reverse I have taken all that out welded on a plate and installed a 670 Predator V-Twin engine using a 44 series Comet torque converter using a comet forward neutral and reverse transmission I’m running 22 inch tires live axle with a 10 tooth 530 chain coming off my transmission going to my rear axle which is 44 teeth that is the largest rocket that will fit under this application if anybody’s got any input on what kind of power I will have the weak points and the strong points I would appreciate it I have also remove the governor off the Predator V-Twin please let me know if you have any input on this setup thank

    1. comet FNR is not rated for the predator V-twin’s hp so that is the weak link. You will need to do compound reduction gearing, or you will risk burning up your belts as the optimal gear ratio is 6:1.

      So, look up jackshaft gearing reduction or something like that and shoot for a ratio between 6:1 and 7:1

  31. I’m building a go-kart for a competition and the engine requirements are
    Max 130cc
    Max speed of about 80kmph
    With no mods done to the engine to reduce or increase rpm
    Can anyone suggest me a good engine with the given requirements?

  32. Thanks so much for all the helpful info! New to carting and hoping for a little advice; we have a little Manco dingo that I picked up a 212 predator and new torque converter for and the predator has been awesome. We recently picked up a Bristers two seater thunder kart which is easily twice the size and weight; I’m wondering about picking up the Predator 301 for it in hopes of having good top end and sufficient torque. I saw in the other comments you suggested the 40 series torque converter; firstly I’m wondering if the 301 is worth the extra money, is it going to deliver the extra speed and torque to climb hills. Second, are there any additional mods or replacement parts necessary besides the torque converter?

    These are just family toys, used on/off road; not looking to race or anything extreme, but would like to get 25-30+ mph and still be able to climb small hills. Any pointers would be much appreciated!

    1. Okay so a 301hp can easily reach 35-40 mph just take out the governor, put in a bored out jet and emulsion tube, and maybe a torque converter for a little higher acceleration. Anyway, that would be around $450-$500 but totally worth it

  33. I am building a minibuggy and I wanted to know what’s the biggest engine I can use with a 40 series torque converter is 25hp too much? Which will put out more power a predator v twin or a Honda gx690? And are there any performance parts for any of these engines?

    1. mike, there are hard to find performance parts, but dont do the predator. The honda beats it hands down every time. I have seen performance exhaust systems for these. The best you could do would be to remove governor (rev limiters are also on the magnetos, so you will have to get ones that dont have rev limiters), rejet, possibly get a bigger air filter custom adapted to the engine, and do the exhaust upgrade. I have seen some custom billet flywheels and billet connecting rods, but they are pricey. Chromemoly push rods,heavier valve springs etc.

  34. What if I want 30 or 40 hp? What’s the absolute biggest type of engine I can use? With a torque converter too? I’m working on something big and I want to be going atleast 80mph

      1. Hi I just recently got a two seater with a predator 212cc on it I was planning on getting a new engine with atleast 15hp but then I saw where some people just mount two 212cc predator engines on one go cart what do you think is a better route. I want to be able to have good torque and still go up like 35-40mph

        1. its never a good idea to do two engines unless u do it for the fun of it and are a pro. Just get the predator 420 and a bolt on 40 series torque converter and you are set.

  35. I am planning on building a gokart/mini buggy and I really want to put a v twin on it but I am curious…does anybody make performance parts for the gx690 or the briggs vanguard engines? Also, for the total cost would I be better off to build a gx390? How much hp can you pull from a gx390 with a full build (cam, ported head, mikuni pumper carb, breather, flat top piston, etc.)? Thanks, good read.

    1. vegas karts does performance parts for the gx390. There are tons of performance parts for the GX390. You dont really need performance parts for a gx690 anyway, just get a comet 780 torque converter and you will be set.

  36. Hey Guy, Just wanted to comment on the 670 v twin. I have had mine in a Yamaha g2 golf cart for 2 years now . We beat the crap out of it most week ends and have had no issues. Are buggie runs about 40 MPH witch is tons fast enough . As for the 18 hp comment above,that test was a rear wheel hp . That is to say 18 hp at the rear wheels . Ours was on a dino and made 22.7 hp ,just a little higher then they say it is . Im going to start a you tube channel of how we made are golf cart and all the mods . Look for Big Joes Garage. Coming soon.

    1. Cool man, thanks. Nothing beats a Honda, and it will always outperform and outshine the predator- hands down. Also, what type of transmission/torque converter are you using? Im trying to build up a mini buggy and am having a hard time with finding a decent reverse/trans.

  37. Im getting a racing go kart for $250 has 212cc Predator but needs exhaust valve, should I fix up the engine and get a tourqe converter or buy a 420cc predator and get a torque converter.

    1. Save up now get a Yamaha kt100 not the mods that fit it. Most of your friends will be scared to give it all its got.

  38. Hi, i have a yerf dog spiderbox 2 seater go cart an was thinking about putting a 16 hp powerland engine on it from ebay. It had a 350 yamaha warrior engine on it but tranny went bad. The rear sprocket has 40 teeth. Would i just need the one inch clutch on the motor an hook straight to the back sprocket? An how many teeth should be on the one inch clutch? I dont want a super amount of take off power.

    1. Sam, you need to put a 40 series torque converter on it or it will burn up the clutch. Also put a 60t axle sprocket on it and a 10T jackshaft sprocket on the torque converter jackshaft.

  39. I have a gocar with balloon tires and have Briggs and Stratton5HP on jack shaft I ordered a predator6.5 can I do wheelies with the new motor on

  40. Hey I need some help choosing and powerful engine, what do you think about this “duromax” 18hp 440cc engine?
    I saw it at homedepod and amazon for a good price
    I’m looking for reviews but there’s good and bad reviews about this engine
    Also can a 13-18 hp engine do wheelies?

    1. depends on gearing, torque, torque converter, weight distribution, and build quality. popular engine is the predator 420cc as well as the predator 670cc.

  41. Hey this Abdulah and I have 2 questions? So I want to build a go kart with push start button, lock, key-remote, control buttons, head lights, revers gear, radio.
    2 I Had a question about engines v twin and others. V twin engines. Can I find v twin with electrical start from other companies, can I power other acc. like LED light bar, speakers, lights….etc through the engine?
    Thx

    1. yeah. most industrial v twin engines (kohler, honda, briggs, predator) have a decent sized charging system (usually between 3 amps to 20 amps). Use the charging system amperage, and voltage (12vdc) to figure out how many watts you can use (watts= amps X volts). Typically 3 amps should be reserved for charging, and the remaining amperage can be used for lights and anything else as long as it doesn’t exceed amperage provided by charge coils.

      1. I bought a go kart W/out engine or tranny. I`m planning to put a 1981 shaftdriven 750 honda seca engine and transsmission on it. How can i hook it up to cv clutch unit i got on EBAY? and is it possible?

        1. Seca was a Yamaha, and like nearly all modern motorcycles, the engine shares cases with the transmission , including the clutch. Why would you want to add a low capacity cv clutch to the mix on top of that.

          Your best bet would probably be to start with a more reasonable motor that suits your experience and skill level. You can always go bigger after you know what you’re doing.

        1. Can. Yes. How? If you don’t know, then don’t try it because it would make many more questiosn for you than you could answer on your own, then you would realize its not a good idea. It is easiest and best to do a transmission, and for go karts that is the 40 series torque converter.

  42. Hi,I have a gearing question . I’m building a helix 150 with a 420 predator no governor, header and rejeted carb. I’ll be running a 40 series torque converter and 18 inch tires.what size sprockets do I need to be able to power slide that big heavy kart around?

    1. I run an 8t on jackshaft and a 54t on axle on my go kart that does wheelies on youtube. You can go 60t or 72 on axle for even more torque. Optimal balance of speed and torque will be a 6:1 ratio for jackshaft and axle sprocket so 9t/54t or 10t/60t is a good all around setup.

  43. Hi I’m bringing a Honda odyssey back from the dead and it was modified to take the Honda gx340 and was wondering if that’s enough power? Or do I go with something bigger? I live in a hilly area so I need power. Also what clutch would you suggest ?everything else is still there including the torque converter I guess you would call it that.

    1. Jeff, If it fit a gx340, then you could put a bigger engine in it (as far as the mounting pattern goes). Id personally get a used gx610 or gx620. If you are going new, get a gx630. As far as the clutch goes, its up to you. Originally you had a 2 stroke engine on those things, so the 2 stroke clutches can be used to engage at a lower RPM range by changing out springs and weights, but they may not perform ideally. A lot of guys use the 40 series torque converter (good for up to 18 hp, but some people use it at a higher hp application with no issues. Another good 4 stroke torque converter is the comet 780. As far as gearing goes, you will need to back calculate to make sure you dont need to swap out sprockets. You want to gear for about 40-45 mph at 3600 rpm, so you take into account tire size, jackshaft sprocket, axle sprocket, high ratio of the torque converter, and any internal reduction that the transmission may have. Also, since the time of this posting, I have found out the predator 670cc engines are just OK (a guy tested one on a dyno and it made 17 hp so there you have it) also, the predator 6770cc engines do not like to over rev, and will fail at RPMS you could run on a genuine honda or briggs with the governor removed. If you were on a budget, you may be able to get away with a 40 series and the predator 670cc, but not modify the engine in the future.

  44. Hi, new to the kart world. So my kids have a carter off road 2 seater go kart. The 6.5 motor locked up. I’m gonna swap a predator 212 on it. I’m not looking for top end but I do want them to be able to climb hills at the hunting club. Can someone recommend what mods and sprocket and chain setup for this type of riding ?

    1. You wont need to mod the engine, just get a different jackshaft sprocket. Typically the 8t 5/8″ bore type C sprocket is the one to get for the best low end torque (it will cut into your top end speed).

  45. i have just purchased a 212 predator to replace a 49cc motor on a power kart. what will i need for a proper swap?

    1. 49cc might be a 2 stroke. You may need to first check the mounting pattern to see if it matches. If it doesn’t match the engine mount, then you may have to drill holes or weld on a new plate. the predator 212cc uses 5/16″ bolts for mounting.

  46. Any thoughts on say the Briggs and Stratton 950 or 1150 OHV engines? I’m looking at those as an alternative to a GX270 since price wise they can be had cheaper with electric start than the Honda GX270. I’m building a go kart for off road use and light Street use. 10 tooth on a toque converter and 72 tooth sprocket with 18″ rear tires.

    I haven’t seen any karts with the newer Briggs and Stratton OHV engines such as the 950 (9.5 lb/ft and 208cc) or the 1150 (11.5 lb/ft and 250cc).

  47. I have a 301. And i bought a clutch for 50 as soon i put it on it burn out. So wat clutch i need for the 301 to run good with no problems

  48. I’ve been looking for a great sounding motor/drivetrain for a “mini hotrod” style kart.

    I love the sound of the big twins… but I wanted something with more looks and less power. I found Lifan V-twin 250s goin’ for around $1,000 new on Ebay. They’re about 14hp, have decent looks (read: CHROME), a 5spd tranny, manual clutch, chain drive, electronic ignition, and that all important twin sound.

    I’m looking to build something akin to a Morgan three wheeler…. big twin up front, drift machine with vintage looks.

    Thought you guys might find it comparable, given all the extras you get… it’s a total engine/tranny package. Sure, you can buy 25hp for the same money… but you can’t buy 10hp, dress up parts, 5spd manual, manual clutch, cheap replacement of all parts, and V-twin sound for that kind of money… except the Lifan 🙂

  49. Hello I have a yard kart with a live axle, a 5hp Tecumseh powersport and 35 chain i was wondering if it would be safe if i upgraded to a predator 301cc with a centrifugal clutch, or if that would be a bit much.

    1. yeah that’s probably too much for 35 chain. If you did upgrade you would need to get 420p chain and a 41p sprocket instead. The 212cc predator is very popular and that might be the best choice in this case.

      1. I have a yurf dog go kart i I’d like to put a bigger motor on it what can I put that I don’t have change everything like the torque converter and all that

  50. Now I see it That is awesome , Thanks the variable speed and torque in the low end gives the wheel the ability to move forcibly then move with a higher rate of rotation and the one speed centrifugal restricts the variation to the speed of the rotation of the output shaft on the engine and the sprocket sets the ratio. We can now move forward armed with the info you gave me. Thank you for clearing up so much confusion, I ride motor cycles and they are a ton more easily under stood. So compound jackshaft and 40 series converter really clears up my confusion, Thanks so much again I’ll let you know what we come up with. Probably be teaching him how to weld so he can weld something himself. Take care and have a great Thanksgiving, Bill

  51. Hello thanks so much for your website you certainly have it going on with all your experience the info you produce is a great source of help and inspiration, I am taking the time to send you a request for info on a manco upgrade you mentioned . I acquired the same 706b with a real new predator 212 6.5 for a 16 yr old and was going to go the route of building it up with hp upgrades as a project but the cost is a little daunting for the kits to end up with something that may not hold up. So my hope is to get a 13 hp engine {on its way} so it will be the work horse, and move on from there, however I was hoping to simply get a heavy duty c clutch for the larger 1” output rated for 13 hp and configure it straight to the axle drive sprocket. With this in mind I havent been able to find out what tooth count would work or what combination I need to carry forward, hoping not to have to go the expense of a jackshaft. So there it is, also I was interested in hearing how you were going to approach your 13h upgrade . We are new to the karting world I am a welder fabricator by trade and trying to give the kid something else besides the computer games. Well thank you for what you are putting out there and thanks in advance, look forward to hearing from you ,Bill

    1. Bill, the kart won’t be able to climb hills and the clutch will wear out prematurely if you do that, even if it’s heavy duty.

      A second option that will cost you $60 more is to fabricate your own jackshaft. Using 3/16″ plate and tubing with an ID of 1 3/8″, and a roundbar with a keyway of 3/16″ . 9t jackshaft sprocket…. See my video for “13 Hp Manco off road go kart” on YouTube as it shows just s few seconds of the setup. You can get a cheap Chinese version of the 40 series torque converter on eBay.

      1. Ok awesome ,I see the ratio with the 9t j shaft and 60 t axle tho the math and geometry of the clutch or t converter is causing pain. Thanks for pointing me in the right direction , so the 40 series comet type or what i found the Hilliard heavy duty clutch will work for this set up, with 18 ” rear tires? Thanks again for your help I’d say I was just spinning my wheels but with the wrong info I couldn’t be sure of even that was going to happen! Thanks in advance , Bill

        1. I forgot to mention the tooth count is 17 with this 1” Hilliard clutch , # 35 chain . or 14t with 40/41 chain. Not sure if there is other sprocket counts . Thanks again, nice work on the refurbish / upgrade on that Manco cart!

          1. Ok, so lets see here. You will need to do the math, but here is my advice in general. For a small engine 4-8 hp, and a clutch, gear for 25 mph max. For a small engine 5-8 hp you can use a 30 series torque converter and gear for up to 35 mph. 35 chain is weaker, but fine for clutch, 40/41/420 is stronger and should be used with torque converter.

            Next is the big engines 8-13 hp. You can gear for 40 mph max speed with a 40 series torque converter. 420p chain is what I use (look up the difference between 40/41/420, its all about the same though. A centrifugal clutch on a 13 hp engine with 18″ tires would need to be geared for around 30 mph at most, and dont plan on climbing up any steep hills. In my eyes, a 7 hp engine with a 30 series on it would be funner than a 13 hp with a centrifugal clutch. I know you are trying to save money, but it is a complete waste (in my opinion) to put a centrifugal clutch on an engine that size. Centrifugal clutches have their place on low end karts, and high end centrifugal clutches are great for race karts. The off road type karts almost always use a torque converter because they have the low end torque to climb hills, and the high end speed for cruising around. I have only seen a centrifugal clutch work on a mini bike for off road use, and it was compound geared through a Jackshaft to go 15 mph.

            Think of it this way. If you try to gear for a high speed or climb a hill using a centrifugal clutch, its like trying to get a manual transmission car moving in 4th gear. Possible, but you will burn something out eventually and have crap acceleration from stop.

  52. I would look for an engine from an old rototller these tend to have larger engines than lawn mowers and they also have a horizontal shaft which will be easier to adapt to your frame. Also tillers are one of those things that people buy because they seem like a good idea but then they don’t work as well as they anticipated and the people sell them at garage sales for a little bit of nothing. Good Luck

  53. Another engine option to consider is the Lifan clone. More expensive than the Predators, but I think less expensive than the Hondas. I installed one on a previous restore I did, ran great.

    Thanks

  54. Thanks for posting all this info; your site has been quite a reference for me while I restore my recently acquired Murray explorer! I was wondering if you knew anything about the predator 301cc engine? That’s what’s was included with my kart. I can’t seem to find any aftermarket parts for it. Do you know if it’s a clone of something? Or whether parts from a similar sized honda engine would fit? Thanks again.

    1. That’s an oddball. There is the honda gx270 (smaller) and the gx340 (larger). If I were you, I would see what carb is used and what size exhaust port is used. If the same carb and exhaust is used between the 270 and 340, then you may be able to get away with performance intake/exhaust. The jetting will be tricky. Do your homework. I wish I could help more.

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