I have been using the Tomar 3 disc clutch in my 120 for the improved class now for three years and it is by far the best set up i have used. My question is, is their a setting for slippage? I have it engaging 50 rpm less than peek torque rpm as per instructions and the problem i have is that it engages so hard that a chain will only last 3 races and then break. It would be nice if i could get a little slip before full lock up. I am using a 2.91 gear ratio and we are still getting hole shots against kids that weigh 20 pounds lighter.
Post by Regan Vehring on Jan 7, 2011 0:46:33 GMT -5
Not sure why it is snapping chains, i use the same clutch with 25HP opens. Maybe the problem is the quality of chain, are you using hardware store chain or a good Karting chain, the tensile strength between the two is night and day. You really don't want it to slip more that usually means less preformance, i'm thinking you don't want it to hit so hard on clutch ingagement, i would make the air gap smaller on the discs. there might be spacers inside the clutch that you could take out to lower the air gap. Hope this helps
Thank you Regan, tightening up the air gap made a big difference and yes i am using chain from my local snowmobile shop, so probably not of highest quality. i will have to get a hold of franklin motorsports and order race chain again. last time i ordered the gold race chain i couldnt use it because i could not find a 1/2 link to work, it was either way to tight or way to loose, a 1/2 link would have fixed problem.
Post by Jim Donovan on Jan 12, 2011 7:17:57 GMT -5
Avoid ever using a 1/2 link they would give you fits. The weakest link in any chain is the master link. But when you use a 1/2 link you will double your breakage problem. If you need to tighten your chain up just a fraction then place some washer under the motor and the motor mount plate (frame). I know there isn't much room and things are very tight under the hood but elevating the engine is much better than using a 1/2 link. This is the advice I give go karters when they want to tighten a belt on a torque converter so it will not slam into engagement when the belt is too loose. Raising the engine will change the center to center distance thus tighten up a loose chain or belt.