Sprockets Engine's chain gear mounting/pinning tab was sheared off!

lazylightning@mail.r

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I was out riding today, and my chain gear on the clutch axle is no longer fixed to the axle! It was sheared off! Now it spins seperately. No tab left to pin it! I don't think I'm pushing too many horses with a stock carb and muffler, but I did port it and increase the compression ratio nicely and it started to get some balls to it. So WTF is with the cheesey flimsly little connection between the gear and the clutch drive shaft? That is so lame!
So now do I have to buy a whole new bottom half or can this clutch axle be ordered seperately? What is the purpose though, if these little engines can't even handle a few HP increase? Should I try to have a whole new axle made custom ordered from special steel and have it made with three tabs/tongs sticking out and have the star gear fitted to it specially for triple protection? This is a major lamer!
I guess welding it is not an option?
 

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i dont get it why you guys always want more power ITS A BIKE! just get the 66cc its powerful enough you start modifying and tinkering around on these cheap engines you open a huge can of problems.
 
Yeah well))) I don't need just a bike. I need a racing bike. Working on a little gearbox too, so I can get up to 60+ on the interstate ;) Next motor is definitely a motocross racing engine. Maybe an 80 cc with 18 HP =) A 29er with 3 inch tires too...

Funny thing is, it isn't really that much more powerful. Just the darn gear lock key was too miniscule. Maybe it was just the place where that particular factory decided to economize.
 
if its a racing bike u need look into honda small engines or other quality engines thats not built with cheap material good luck dude :)
 
if its a racing bike u need look into honda small engines or other quality engines thats not built with cheap material good luck dude :)

For sure!))) This is all I have for now though. I may be able to re-pin it with something. It will take alot of thought to find something that hard and small and be able to shape it with hand tools lol)
 
why not replace the woodruff key with a new one? maybe a new sprocket.
the pics are too blurry for any detail.
the keyway on the shaft damaged?
could be the nut was loose on the shaft.
the shaft can also be replaced.
 
Yes, that's what I want to do. There is damage, the mating surfaces have like .2 - .3 mm deep gouges in them and there was only metal powder left from the old woodruff key. I thought it was in two pieces, but when I dug in with a tiny screwdriver, only powder came out.
I will have to dremel the lip edges of the inset cut to make them square again. The inset for the woodruff key is very short (at full depth) on the clutch shaft. I want to try to dremel it to full depth the full length of the inset cut for a longer(full length) rectangular woodruff key. If the diamond bits will do anything, I may make a second set of inset cuts for a second woodruff key. I will have to make woodruff keys from a piece of hard steel that was part of a thick saw blade used to cut railway rails with. I have something that I can cut a tiny piece off with and then I can file it a little to get it perfect. Very hard, but not brittle "spetz" metal.
Maybe the nut was just a little loose, but it was still snug immediately after it happened when I opened it. I think I will lock those threads up tight with something when I put it all back together...
 
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why not replace the woodruff key with a new one? maybe a new sprocket.
the pics are too blurry for any detail.
the keyway on the shaft damaged?
could be the nut was loose on the shaft.
the shaft can also be replaced.

You know, I took everything off and it looks like I would have to take that crankcase apart to get the shaft out. I was hoping it would slide out somehow, but to no avail...
 
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