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dno92

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Whats up everyone, This is now the second time in three weeks that the bolt that holds my clutch to the crankshaft has snapped entirely while riding it. I have a torque converter on it but with how many people i've seen with this torque converter there is no way that this is a common issue. Im using a 6mm course thread Grade-8 bolt from Ace hardware that was 50mm in length after needed the extra length after putting the T.C. on. After the first time I used a 5/64" drill bit and tap set to remove the bolt from the crankshaft and I chalked it up as "that was a bad bolt" but now this is a little ridiclous. I made sure not to overtighten and I was able to use each of these bolts for about 3-4 weeks with no issues before this happened to both of them.
Any ideas on why this keeps happening? I feel like its very hard to over tighten these bolts and with it being able to run for a few weeks without issues has got me stumped. Anyone else have this issue? Pictures attached. As you can see Ive basically taken the entire bike apart and replaced damn near everything on it to my liking. I know this little bike inside and out so any help would be appreciated! Thank you!!
 

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Personally, I'd like to think that there would be an M8x1.25 pitch Grade 8 flanged bolt used on the end of the crankshaft, that is a very high-stress area. Depending upon the OD of the crank end, can you possibly re-drill it and tap it for an 8mm bolt? And maybe use some red loc-tite on the bolt threads?
 
Personally, I'd like to think that there would be an M8x1.25 pitch Grade 8 flanged bolt used on the end of the crankshaft, that is a very high-stress area. Depending upon the OD of the crank end, can you possibly re-drill it and tap it for an 8mm bolt? And maybe use some red loc-tite on the bolt threads?

I would think it should be at least an M8. I can't believe it specifies for an M6. I might just replace the entire drive shaft with one that holds a 5/16" thread. It seems strange to me that nobody else has had these issues. I dont have the room to change it to an M8 but It seems with how much stress it's under it needs at least that. If I locktite those threads shut then replacing the belt when it wears becomes a giant hassle and the bolt could snap off then anyway.
 

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