Gem car super kart clutch help

[GEM4SPEED]

Hello my name is Chris and I am new to the go kart world, but not to engines and autos. I need help picking a clutch and sprocket for my project .. This is what I have a electric gem car that I am turning into a gas job.. The gem car is a 2 seater weight is around 1200lb I know that's a lot, it was 1600 with the batterys. I am installing a yamaha 440 into it. This engine has a 1" shaft and not tappered. Clutch in the pic is the old one from the sled, can not use. need a gokart centrifical and sprock. The front diff has a 5:1 gears , Wheels are 165/70r12 . What I am looking for is a strong on/off road rig with good low end torque. Not super worried about max speed 40mph would be good. The engine is making around 15-20hp

 

[GEM4SPEED]

More pics

 

[itsid]

I hate to tell you that,
but a centrifugal clutch will be a huge PITA with a thing like that.

Do yourself a favour and get a matching Torque Converter, it's more than worth it.
if you have use the driven that's maybe still on the sled and find yourself a belt for it.
(that's the best option) if it's not.. try to find the driven from a similar sled,
and if that too fails.. get a comet but a 94C or 103 I'd say.

to be honest I doubt it's just 20Hp it's closer to 40 IIRC. (well if it's a Rotax 440 we're talking about)
that means you'd need a very hefty TC and that's going to be expensive!

'sid

 

[OzFab]

This engine has a 1" shaft

Are you sure? Most engines of this type are 1.25"

Clutch in the pic is the old one from the sled, can not use.

Why?

The engine is making around 15-20hp

Not to sound like a broken record but, again, are you sure it only produces 15-20hp?

IF it's a 1" shaft & only produces 15-20hp, you may get away with using something like a Noram Star clutch

 

[GEM4SPEED]

Yes 1" shaft and the sled clutch are to big. Will not mount down on the diff... Really want a centrifical clutch. Might think about a torque converter. Anyone have a link to one thAt will work.. So I can look it over

 

[landuse]

Yes 1" shaft and the sled clutch are to big. Will not mount down on the diff... Really want a centrifical clutch. Might think about a torque converter. Anyone have a link to one thAt will work.. So I can look it over

Fabroman gave you a link. It won't work if the engine pushes out 40HP though. No centrifugal clutch will

 

[OzFab]

It won't work if the engine pushes out 40HP though. No centrifugal clutch will

Not true; the Noram Trilobe series can handle up to 50hp but are only available in belt drive & will probably cost a kings ransom...

 

[GEM4SPEED]

Looked over the link, I like the clutch but do they make one that can handle 20hp and think I need like a 4500 rpm engagem very big kart

 

[GEM4SPEED]

Also let's talk sproket

 

[landuse]

Not true; the Noram Trilobe series can handle up to 50hp but are only available in belt drive & will probably cost a kings ransom...

Hmmm. Didn't know that. Thanks

Also let's talk sproket

Thats a funny language...

 

[GEM4SPEED]

Thats a funny language...[/QUOTE]

sprocket sorry

ALSO I WAS WRONG ON THE ENGINE IT IS A 340 NOT A 440

 

[OzFab]

Ah, that makes a difference, your numbers make more sense now...

4500rpm engagement speed sounds a bit high...

If a clutch can handle 50hp, it will definitely handle 20hp; I don't understand the problem

 

[GEM4SPEED]

Ok think I am going with the enforcer clutch. Now just need help picking the sprocket..

 

[OzFab]

Ok, we have the reduction ratio of the diff but, what we still need is:
-tyre diameter, from ground to top of tyre
-number of teeth on the clutch

Now, based on the tyre size you provided, I'm estimating tyre height to be around 21"; using that number, you need a total 8:1 ratio to achieve 40mph@5000 engine rpm but, will that provide enough torque?