centifugal clutch
 

Hi,

Hope this in the right place, and it is my first post so go easy on me :)

The kids and i have been making a go kart and we gave it it's first test run last night. Its a 6.5hp honda copy with a 12 tooth centrifugal clutch driving a 53 tooth rear sprocket, on 18 inch wheels.

Anyway after about 5 mins buzzing about a field the clutch was smoking and while not "red hot" i wouldn't want to have to touch it. The crank shaft end was also bluing from the heat on later inspecion. Acceleration was slow.

Does this mean that with the setup I have the weight of the cart/rider is meaning tha the clutch is perminantly slipping and likely to wreck it?

Cheers


Aidan

Can you post a picture of your set-up?

Which clutch is on it? Just the standard type one that you'd get at Northern Tool or Tractor Supply? If you are doing a lot of stopping and starting again, it is not that uncommon for them to get pretty hot. Other things come into play such as what size tires do you have in the back? Metalstudman1 is right. Post a pic and we can advise. You can attach a pic to your post. Just scroll down when making your post and look for the button that says Manage Attachments.

The "ole Skool Rule of Thumb" for centrifugal clutch ratios and tire diameter went something like this...
6" tire diameter = 2:1 sprocket ratio

So 18" tires, being 3 times larger, would require a 6:1 ratio, more like a 12T / 72T sprocket combo.

There is always fine tuning that can be done, but in the last century, tese are the numbers a lot of us used as starting points.

A "blue" crank is a definite indication of slipping, and imminent failure. Start with a NEW clutch and a 72T sprocket... you'll be surprised at the difference. You also need to allow for "hook-up," so the clutch can cool too. Constant stops, and hard accelerstion, will fry just about any combo.

Thanks for the reply. decided that a torque converter and layshaft arrangement will be the better option so hopefully it will arrive on Monday and we will see where we go from there

I thought the engine would be the expensive bit lol

Aidan