4 stroke clutch adjustment

This is why I wish i'd taken pics...
After bolt is off, the "sleeve" is next. It's between the bolt and the clutch bell, and approx an inch in diameter with a shoulder that sticks out about an eighth inch from clutch bell. Use a thin yet strong too like an old kitchen knife, carfully prying against the bell. Try not to gouge the contact surface as they slide against each other when clutch disengaged! It'll be about a half inch before it'll come out.

Works much better when it's working, huh!

The thing is, it needs constant re-lubing. Every single time the engine is running and you aren't on the throttle to have the clutch engaged, that bushing will be spinning, eventually throwing out the grease and binding up again. I could only go about four days myself, however, I had probably 20 minutes of idling each day at long stop lights.

After you remove the bolt and washer the hard part is getting off the racer that the clutch bell spins on.it's not easy to get the racer off sometimes. It's the part that slides over the shaft with a key slot in it that holds the clutch bell in place and also allows the bell to spin freely when the clutch isn't engaged. I ended up adapting a flat wrench that is used normally for tightening the blade on my table saw. The flat wrench is only a little more than an 1/8 th inch thick and the open end is as wide as the outside diameter of the racer where it slides inside the clutch bell, but narrower than the lip of the racer that holds the clutch bell from slidding off the shaft, then I beveled the points of the wrench to resemble a pickle fork like you would use to remove a nuckle joint on a car. Then I place the modified wrench flat against the bell and strike it with something to wedge the racer out. Once I'm able to wedge the wrench in between the racer and the clutch bell I can then just use the leverage of the handle to pull the racer the rest of the way out. Without some device like this It's a pain in the butt getting it off, at least mine have been and my key isn't even tight. THe racer seems to get stuck on the shaft.

jacliny said:

Does anyone know how to have the clutch engage at a higher rpm on a china 4 stroke (dont know how to spell it! I think its pronounced washing like the machine! lol) with a grubee gearbox? Mine engages at a complete idle, even when pull starting it slightly engages. Needless to say its almost unrideable! When you engage the gearbox i have it idling so low it stalls and if i boost up the idle it then crashes in horribly then stalls! Well, thanks guys ahead of time i'm sure someone will have the answer.

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I haven't had that problem in the 15 grubees I've built but I lubricate the clutch before I install it and I get a tight fit on the shaft key. I read about an idea on a thread by a guy called Cheetoh and I tried it. Since I tried it I have used it on several grubee gearboxes and the improvement in clutch sensitivity is remarkable. The attached picture shows the method - drilling holes where shown. This makes the clutch more responsive to the spring so it doesn't clatter when idling. The new clutches have a stronger spring but even with those the drilling of 9 holes really helps lighten the clutch segments so that they retract better at low revs. I cannot speak highly enough of this little technique and it will not make any situation worse only better. You need to take care to clean the drillings off the clutch before you insert it back on the shaft. Those clutches are supposed to be inserted spring inwards towards the engine but it doesn't matter much and you can reverse it to even the wear on the pads. Jacliny's problem suggests that either the clutch needs lubrication or the spring isn't properly in the groove and has come out. Probably the former more likely.

I had a similar problem at one point, it may not have to do with the gearbox at all, it diddn't with me at least. look at the the throttle on the engine, if it isn't resting against the little black plastic screw then the problem is with your throttle cable, not your engine. check the place where the cable feeds into the twist throttle and where it feeds to the throttle on the engine itself, it may be caught.