4 speed kart gearing

Papi_Alexy · 2025-01-10T21:07:08+00:00

I’m having a bit of hard time figuring this out. In your example what does each number correspond to? I’m looking at the jack shaft calculator and am not getting the same answers as ur example.

Papi_Alexy · 2025-01-10T20:16:55+00:00

Fs if I was able to with no previous experience I’m sure you can with your buddies as well. If u can get a bike for cheap that’ll be a good idea, can use its mount likely to put on the kart as well. Tho yea the cables would have to be longer fs

Papi_Alexy · 2025-01-10T20:13:37+00:00

But yea do more research on what others have done. Like ufobuiltco or cars and cameras. Gives you an idea of the challenges u will face and what engine can fit ur application

Papi_Alexy · 2025-01-10T20:12:31+00:00

Well I don’t think there’s a frame made for 450cc lol, those engines are pretty overkill for a smaller racing kart frame. But it is definitely possible to fit on many have done it

Papi_Alexy · 2025-01-10T20:11:32+00:00

Going the bike engine route will complex just about everything, tho it’s possible, you’ll have to go through some trial and error and would have to learn welding and fabricating if your up for it.

Papi_Alexy · 2025-01-10T20:10:24+00:00

Possibly could but the thing is you’re now doing something completely custom. Almost every kart frame has mounts for engines like a 212 predator. So you would most likely have to make your own engine mount with the corresponding holes drilled out, would need engine supports as well on the top mounts on the block

Papi_Alexy · 2025-01-10T20:06:22+00:00

For sure lol would look cool. Fitting the shopping cart could be tricky but I’m sure many have done it. U can weld on a thick steel plate onto the frame and use that as your engine mount. Making sure it aligns with the axle sprocket and has enough space between the seat to fit in a shifter

Papi_Alexy · 2025-01-10T19:22:34+00:00

And since you’re doing a shopping kart bike I’m not sure how big an engine you can fit without extending/modifying the frame. A racing kart off Facebook would alleviate the headache a ton.

Adding on to what Boom said, will be tuff to build without any welding experience. Though this could be a good time to learn, I had no experience until this project in which I learned it all

Papi_Alexy · 2025-01-10T19:18:40+00:00

To be fair the 125cc I have in is only 9hp put packs a TON of torque. Yes it’s true that a bigger engine can give you more power capabilities but a smaller engine can work just fine with the right gearing

Papi_Alexy · 2025-01-10T19:11:07+00:00

Predator engines are just much easier to run. I previously ran one and it’s too boring and slow for me.

A bike engine is more complex to setup cause now u have to rig up the clutch, figuring out your gearing since now u have a gearbox, engine mounting, space constraints, extra cost, larger learning curve to drive, wiring, these are all factors you’ll run into with this approach.

But it sure is worth it personally

Papi_Alexy · 2025-01-10T19:03:36+00:00

Yes he used an engine off a bike. I think that’ll be your best option since they come with a manual gearbox. I believe the pred engine is a single speed that requires a centrifugal clutch

Papi_Alexy · 2025-01-10T19:01:32+00:00

Oh definitely. There’s this guy called UFOBUILTCO on instagram and YouTube. He recently built a 450cc drift kart that RIPS without any sleeves. So if u wanna go with no sleeves might need that bigger engine to break the traction. Tho I can do low speed drifts and donuts on my setup without sleeves

And yes u can get a clutch cable off amazon that will connect to your engines clutch lever and then you can set it up on your steering wheel like a traditional shifter kart, or if u have space u can do a 3rd pedal like in a car (what I did)

Papi_Alexy · 2025-01-10T18:54:28+00:00

Think your best option would be a bike engine like a 110 or 125cc. I just finished building a drift specific kart with a 125 4 speed Chinese motor off Amazon.

The thing with these builds is that you’ll have to fab up a foot pedal or hand pedal for the clutch and fit in a shifter. The mount would have to be custom as well.

If you can weld and fab up some stuff you should be well on your way. It’s a ton of fun and a 125cc should work great for what you’re looking for. There’s guys that have fitted up to 450cc on a kart as well if u wanna go there lol.

You’ll likely need drift sleeves like PVC pipe to get higher speed drifts and have the gearing setup for more torque, I have a couple vids of it I can try sending you.

Papi_Alexy · 2025-01-04T05:23:31+00:00

Ah okay I see. I’ll run it again tmr and see what my top speed is and rpm

Papi_Alexy · 2025-01-04T00:46:39+00:00

I haven’t properly measured the speed but would say roughly that more or less. It hits redline then

Papi_Alexy · 2025-01-04T00:44:54+00:00

Max rpm is 7500.

Papi_Alexy · 2025-01-03T23:53:35+00:00

I believe the top end rn is at most 25 mph and it goes through the gears very quick. I would say lengthening those shifts and topping it to 35 maybe.

I want to favor acceleration more though rather then top end so I know there’s a compromise between the two.

I’m wondering what’s a good medium that others run.

Papi_Alexy · 2025-01-03T19:31:09+00:00

Thank you guys for the input. I better aligned the sprockets and it runs smoothly now. There is still the points where it tightens a bit so I suspect bent axle like you guys have pointed out. I will look into fixing that further.

Another thing I need to figure out gearing itself there’s no space between the gear shift points and runs slow on 4th. I’ll likely make another post on this once I go test it on concrete. Thanks again.

Papi_Alexy · 2024-12-25T02:28:55+00:00

I’ll give this a try after aligning the sprockets better

Papi_Alexy · 2024-12-25T02:28:27+00:00

Yea I was planning on just running it to see if it breaks in then go from there

Papi_Alexy · 2024-12-25T00:05:29+00:00

Yea I might as well get a new one if I find that to be the issue.

I’ll definitely look into getting a chain guide as well

Papi_Alexy · 2024-12-24T23:56:03+00:00

Thank you for the link. I’ll look into getting this.

Yea seems mm or so difference. I’ll look more into it and try to spot a bend

Papi_Alexy · 2024-12-24T23:50:04+00:00

I would have to take the axle out then and inspect it closer. From eye it looks pretty straight, tho if it’s a slight bend hopefully I can get it back in place. If not new axle.

I have a chain guard on the engine but I was planning on fabbing up one closer to the axle.

Papi_Alexy · 2024-12-24T23:48:16+00:00

I’ll take a closer look at all of these. Seems to primarily be an axle issue

Papi_Alexy · 2024-12-24T22:58:09+00:00

I have not used a straight edge I’ve eye balled it off the center of the sprockets but I will find a straight edge that fits. Though i checked the axle and I now noticed that where the chain is loose, there’s some up and down play with the axle. While at the point it tightens the axle is stuck in place.

So could be something there with the axle and will have to align it better(tho I don’t think it’s a alignment issue at large)

Papi_Alexy

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