Go kart thread Pic is predator 212cc engine. Me and three

If you don't blow it up by shifting to 2 gears at the same time it's as easy as 2 pulleys and a belt. May take some cleverness due to horizontal shaft to vertical shaft.

>>1178278
>old lawnmower transmission
like a riding lawnmower?
aren't those vertical shaft drives?

>>1178313
>>1178312
Is there an easier way to pull it off? A lawnmower was just our first idea because we knew they have their own little transmissions. Is there anything else that could work that is relatively cheap? We were joking around and saying we should just go pull a transmission from an old civic but I feel like those would be a little big.

>>1178322
Most practical would be a torque converter for about $100, it works like a CVT and it will make your shit get the fuck up and go at all speeds but it eats 1/3 of your budget. Second is a lawnmower transaxle like you want but it will take some adapting. Third is getting lucky and finding a 2 or 3 speed gearbox for off-road karts but that may just run as much as a CVT.
You could always do engine mods, a free one is to remove the governor to bring your limit from 3600 to 5500. Stock springs float at 5500 so it can't possibly go any higher stock. Of course there's a risk of failure but Ive never seen or read about a 212 rapidly deconstructing itself with the governor out unless it was getting fucking abused held at redline for a long time or running other power adders without proper supporting mods. Changing the intake to a pod, exhaust to a pipe, and jetting the carb should give you an extra 3hp at peak for probably $50 or so. If you can find a gx160 head it bolts right up with almost no modification and ups the compression ratio from 8.5:1 to about 10:1. Make sure you use 91 with this though.
Skinny tires will help too, try and get those rounded profile ones rather than flat for less friction since you're likely not going to be lighting up the tires with a 212. Unless it's going to be a course rather than straight line then you may want a little more traction. Do a live axel if you can rather than 1 wheel drive to increase acceleration and limit wheel slip. Make your chassis as barebones and light as you can but still stiff. You can do a reverse trike with 1 wheel In the back for less weight and friction but you may get wheel slip.

>>1178356
Cheapest option is just a centrifugal clutch

>>1178356
This
A torque converter is well worth the money on a small go kart or mini bike

Running a centrifugal clutch and having to compromise with just a single gear sucks.
You add some sort of complicated gear change it will be more expensive, more finicky, and most importantly it will be heavy. You dont want to add a bunch of weight.

Also dont buy a cheap centrifugal clutch, they glaze really quickly, especially if you gear it for top end speed

>>1178278
Why not an old quad and adapting the components to your go kart frame

>>1178278
Fuck the trans. If its a longer race like a 1/4 mile on a go cart. Get a used side shaft motor, centrifugal clutch, and used go cart or 4 wheeler. Put a smaller sprocket on back and larger on motor. You wont be much off the line but u can top 50 or 60mph easy with that motor and gears. Gains should far exceed the launch and you will smoke them

>>1178312
>>1178322
Open the mower trans and take out the second and 3rd gear, grind down the teeth or make a spacer and just run it as a 3 speed, no chance of shifting into 2 gears which is what fucks over those transaxles

What is the best way to build a frame for the kart?

>>1178624
"I" beams.
This way if their is a fuel fire the frame won't melt.

>>1178684

what if he plans to run his go-kart on jet fuel? WHAT THEN?

>>1178624
I've always sat on an idea involving 2" Sch80 PVC.

>>1178706
Wat?

Decided to go with a reverse trike for the frame. I'm just cutious, instead of going with the predator, and having to invest in a torque converter and all that, if I managed to find an old dirt bike engine and convert that. Are they really that much better?

>>1178826
>in general will rev twice as high
>will have anywhere from 3-10x more horsepower for the same or less displacement
>has a real gearbox and clutch system

Of course its going to be better. But thats not really the point of a small go kart is it?
Its not supposed to be a dirtbike with 4 wheels

Its supposed to be a small thing made out of lawnmower parts that simply has a stop and a go pedal.

Wanting to make weird custom thing that isn't quite a cart, and isn't quite a reverse trike (honestly, it will be a prop replica of a vehicle from a game). What would you think of something like http://www.motopartsmax.com/index.php/main_page/product_info/cPath/21_88/products_id/15403 being used?

Perfect, there's already a thread that I can put my retarded idea into.

I was walking through Harbor Freight a bit ago and saw those Predator engines. Immediately wanted to build a go kart. Started talking with my dad, and we came up with a retarded idea that I love. Two engines, one controlling each rear wheel, and oprarated by hand throttles, with brakes in the front, each controlled independently by two foot levers. No conventional steering, only the tank controls of the two engines and brakes. What do you guys think? I could weld up the frame myself, and probably use centifugal clutches, and steal some brakes off old motorcycles or maybe just buy a pair if they're not too expensive.

I also thought about the possibly of having the front axle pivot maybe 5 degrees in either direction to aid in the turning. You wouldn't control this, it would be dictated by the power you give the two engines. Would that fuck everything up? There would definitely be a learning curve, but that's part of the fun.

How big should the engines be, you think? Would two of those 212s would be overkill? They're what I'm considering right now.

Any other thoughts? How retarded is this? Keep in mind it'd just be for shits and the novelty of such a weird control scheme.

>>1179214
already been dun befo
https://www.youtube.com/watch?v=3DzfL2wAOe4&t=916s
https://www.youtube.com/watch?v=f0T_g5FpMVg

>>1179224
whoops dont know how that time skip ended up in the first video

>>1179224
>>1179225
Figured there's something like it out there. Pops and I also talked about 4 engines like that, we'll see how they make out I guess. Nice to see how they're doing it though, thanks for the links.

also

>fwd, even temporarily

>>1178717
Make it out of 2" Sch80 PVC. How was that unclear?

If I were to get a torque converter, would it require a clutch too? Or does the torque converter have this kind of built in?

>>1179768
its a cvt. it uses belt slip as the clutching mechanism. (thats why car cvts are shit and dont last long but its totally fine for a kart)

>>1179768
Look up what a TC is.

>>1179776
>>1179777
Okay, thank you. I had another question regarding sprocket ratio and all that. The cvt that I'm getting comes with a 12 tooth sprocket. Now, I know just by itself, according to: http://www.bmikarts.com/Gear-Ratio-Speed-Calculator-MPH_ep_84-1.html
That with a wheel diameter of 9ninches, a clutch gear of 12, a driven sprocket at 24 teeth, and revolutions up to 5500, it says that it would be able to reach 73 miles per hour.
My question is, how does this work out when the driving sprocket is attached to the torque converter? And is this ratio a good one for what I'm trying to do, which is race go karts?

Will it work if you instead use a generator and drive the wheels using a series coupled electric motor?

>>1178278
I would say just invest in the predator engine or see what you can do with craigslist frames (used) + a new engine will be your best move.
I am not sure how you would convert the driveshaft to have the correct orientation but maybe I'm a fuckin' idiot.