Centrifugal 2 stroke HT - Centrifugal Clutch + Pull Start

[arkives1]

Pull start and centrifugal clutches

Really, been pedal starting both of my centrifugal clutch engines for months now.

The pull start works great once you replace the lousy rope with something better.

I don't know what kind of engines won't work with both starting methods. I have two bikes and both can be started either way. I agree with skyliner that the darn pull starters are pretty flimsy. The last one I got seemed to have a decent rope and the little tab that engages the engine seems to be a bit heavier but still appears to be plastic. I'll probably end up fabricating new tabs for them eventually.

 

[cpuaid]

Skyliner70cc and Arkives1... thanks for the heads up on the info. was gonna do the pull start upgrade but didn't realize the assembly was so flimsy and that it may require a wider crank. helped install a centrifugal clutch and it was a pain in the rear.

 

[iron_monkey]

Main problems:

Sometimes the clutch makers haven't pre-bored the bushings so the clutch bushing can't slide down on the crankshaft enough, the result is that the clutch sticks out so much the clutch cover cant even go on and the gears dont overlap enough. You will need to bore it out with a grinder if thats the case.

Sometimes the clutch gear can sever itself from the clutchbell, maybe the clutchmakers didnt put enough epoxy glue. In that case you will need to somehow weld/braze it back in, or glue it back in with JBweld or some other high temperature epoxy(I did this). To be safe epoxy must be able to withstand over around 400F, I bought an epoxy that was only 300F and it failed. Perhaps the clutch got too hot (it does get very hot - untouchable hot), or maybe I simply havent washed it properly(I should have directly put detergent on the bonding surfaces as theres an oily film thats fairly hard to wash off). The last time I did directly put detergent on the surfaces in washing.

Sometimes the inner clutch assembly simply isnt made properly and it vibrates too much while engaging or at low throttle. I dont know what exactly causes it, I just bought another clutch.

From another thread, it appears the main bolt must be loctited, otherwise you may get a cracked bushing. Do not excessively torque the bolt either, it must be firm, but dont need to use all of your strength.

 

[arkives1]

Great information IronMonkey. I haven't had a clutch failure yet, I did have one defective centrifugal which was replaced immediately by Powerking. I still have one engine which has a small gear that I cannot remove yet.It needs to come off so the centrifugal can go on.