Other Stuck bolt on crankcase cover

HeyWaitUp

HeyWaitUp

Hello all...

I'm attempting to get the left crankcase cover off of my sons CRF70F and the front most bolt it stuck and half stripped. No amount of elbow grease with an 8mm socket has been able to even budge it. I'm afraid to keep going on it before I strip it completely. Any ideas on how I might loosen this stubborn bolt?
 
SRAD97750

SRAD97750

Moderator
Staff member
I use an impact gun on tight hardware with a 6 point socket.
You need to know exactly how to use an impact gun though. I do not recommend it to anyone who has not used one regularily. -BIG DAN:thumb:
 
PALMER84ONE

PALMER84ONE

It has been covered on another subject bolt but you can do a couple things:

pound a next size smaller on it SAE or Metric.
Grind a slot in it and hit it with an impact driver.
Weld on it and grab it with vise grips.
Etc.
 
HeyWaitUp

HeyWaitUp

So after banging my head against the wall over this stupid bolt and trying everything under the sun aside from drilling it out or torching it...my friend brought to my attention that if I grind the head flat, the cover should slip right off. I don't see why this shouldn't work because there are no threads in the cover. Then with the cover off, a good 3/4 of an inch of the bolt will be sticking out that I can get a wrench on it.

I'm gonna give this a go tomorrow because at the moment a baby is sleeping above my "shop". :shocked:
 
O

ossagp

that will work, and you will have it off. i think before i went that far and possibly end up breaking it off I would take one more step. then go for the grindoff. take a ball peen hammer, hammer, tap, beat the bolt straight on the head until you have to pound an endwrench of good qality over the head of the bold and it fits really snug. try to see if the heat, the beating etc has stretched and mishapen the shaft enough, and loosened the corrosion enough to let the bolt back out. heat the case the bolt threads are in of course, instead of the case the shaft passes through.
 
HeyWaitUp

HeyWaitUp

Thanks for the tips guys. I ended up grinding it off, but some of the other techniques mentioned I'm sure will help in the future! About halfway through it came loose and I was able to twist the remainder out with pliers. Me - 1, Honda - 0!

Side note, after removing the cover it looks like the flywheel has some rust/dirt on it. Everything is running fine but I should probably try and get that rust off, right?
 

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