Clutch smoking now...

[tinknocker]

Just finished the go kart, and the clutch started smoking in like 5 min of use. Its a 13hp engine, 13" tires, 12T clutch, 54T Sprocket. Changing the sprocket isn't really an option because its kind of pressed onto the key on the axle along with every other part on the axle... plus the clutch is rated for 13 hp and was quite a bit of money...
ideas?

 

[r_chez_08]

Smaller tyres? Your gearing should be ok. What terrain are you using the kart on?

 

[devino246]

54 tooth is a bit small. Your only other option would be a jackshaft to gear down a tad.

 

[tinknocker]

Its made for roads, paths, and flat land. No hills, ramps, etc...
Would a heavier duty clutch work? The one clutch i have is rated for 13 hp, which the engine had stock but i removed the governor so it might have a bit more now. there was one i found that was rated 14-17hp... how about that?

 

[tinknocker]

CORRECTION! I have a 14T clutch, not 12 because the shaft is 1"

 

[Russ2251]

80 to 85 tooth (assuming #35 chain) would make kart a lot more responsive...and clutch won't smoke.

 

[r_chez_08]

Yeah that gearing is a bit steep then, with 14:54 it is just under 4:1.
You could either get a bombproof 40 series for $300-350, get a larger axle sprocket, smaller tyres or a jackshaft.

 

[tinknocker]

its a 41 chain. i dont think 80-85 tooth would fit because i only got 13" tires. i didnt want to change the sprocket, but if i have to i will.. cuz im not spending 300 on a clutch lol

Im not worried about low end torque because even with the 54T Sprocket the thing literally accelerates faster than my mustang.

What size sprocket would i need to guarantee no smoke? would a 60T or 72T work better?

 

[landuse]

What size sprocket would i need to guarantee no smoke? would a 60T or 72T work better?

Anything would be better than a 54 at the moment. If you can fit a 72 with the size tyres you have, then go for it.

 

[tinknocker]

Anyone know where to find a cheap 72T sprocket for the 41 chain? i found one website but the sprocket is like 70$...

 

[Blazkowiez]

Not for 13" tall tires, a sixty is as large as you can go.

 

[tinknocker]

well ****.... guess im adding a jackshaft... What size gears should i get to make it so i have a reliable kart

 

[tinknocker]

T5314-72 SPROCKET 72 TOOTH 4 INCH BHC 11-3/4" 64.50


Thats the largest 72 tooth sprocket i saw and its not even 12".... sooo 72 should fit my 13" tires just fine right..

 

[r_chez_08]

Yes but you will have 1/2" of ground clearance. For $70 you could put a jackshaft on.

 

[anderkart]

Its made for roads, paths, and flat land. No hills, ramps, etc...
Would a heavier duty clutch work? The one clutch i have is rated for 13 hp, which the engine had stock but i removed the governor so it might have a bit more now. there was one i found that was rated 14-17hp... how about that?

This 10-tooth clutch model would solve your problem: http://www.out2win.com/catalog/noram_enf.html
Although its expensive and an outboard-only mounting style.

 

[Wim]

You haven't got any lube on the clutch shoes by accident?

 

[tinknocker]

the only place i could really put the jackshaft is on the back of my seat... i guess that could work. and no lube on the shoes, made sure of that. the gearing is like 3.8:1, so im pretty sure thats the problem. i know nothing about how to gear a jackshaft tho, that seems complicated. like to i have the same size gear that runs the sprocket and a larger one that runs off of the clutch? how much larger, what size clutches, what size shaft, is mounting it on the rear seat safe, how do you tighten the chain that goes from the shaft to the sprocket, etc...

 

[Wim]

I'd keep your clutch and rear sprocket, and build a jackshaft with maybe 22T? input and 14T output.

This would bring your ratio down to about 6:1.
An 18T input would be ~5:1.

calculator

How and where to fit it depends on your setup. If you want to keep it simple and not worry about jackshaft adjustment, mount it with a little bit of slack in both chains and take it up with adjustable/spring tensioners.

 

[tinknocker]

i tried using that calculator and when i put in 14T clutch, 54T sprocket, 22T Input, 12T Engine driver, i get 7.07:1. am i doin somethin wrong?
sorry i just have no knowledge of jackshaft setups, where would be the best place to buy the shaft kit and tensioners?

 

[tinknocker]

would a kit like this work?
http://www.bmikarts.com/item/Go-Kart---Minibike-Jackshaft-Kit-400950-1267

With a 14T and a 10T? or is it bad to run the same size input as clutch. i did it on the calculator and it said 5.4:1 i believe