Am I screwed here?

DrMcNasty

DrMcNasty

New Member
So the monster I bought looked ok at first glance but now that I have started to dismantle it, I have found a problem.

The bottom back bolt thread on the left crankcase side, where the crank case cover threads into is cracked in half. Someone did a number on this poor thing.

1. Will this be a problem to only have 2 bolts in the crankcase cover?
2. Will this broken bolt hole be a problem to put on the chain cover? It looks like the bottom hole on the chain cover may try to mate up to this spot.
3. Should I be looking for the left half crankcase to replace this?

Picture shows the carnage.
 

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CLEC66

Active Member
I don't think I'd be sourcing a left case just yet. Slim chance you'd find one with close numbers. Think at worst the chain guard might have a little rattle. That looks like a hard repair, probably could get it welded and drill/rethread hole. I have a bike with same issue but doesn't make any noise while riding.
 
red69

red69

Well-Known Member
I don't think this is a big problem. Two screws should hold it, but for me, I would have the area welded and drill and tap it to accept the screw.
 
DrMcNasty

DrMcNasty

New Member
red69 said:
I don't think this is a big problem. Two screws should hold it, but for me, I would have the area welded and drill and tap it to accept the screw.
Click to expand...

I wasn't sure if that was something you could do on these cases, since they are aluminum?
 
DrMcNasty

DrMcNasty

New Member
CLEC66 said:
I don't think I'd be sourcing a left case just yet. Slim chance you'd find one with close numbers. Think at worst the chain guard might have a little rattle. That looks like a hard repair, probably could get it welded and drill/rethread hole. I have a bike with same issue but doesn't make any noise while riding.
Click to expand...

Good to know that yours is living with 2 bolts.
One thought I had was to JBWeld a stud into it and put a nut on the outside instead.
 
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allenp42

Well-Known Member
As red69 suggested, I would get it welded up and re-tap. Once you use JB Weld, the welder will not be your friend if you decide later to fix it correctly. From what I understand, it makes it very difficult to weld w/o removing all traces of JB. Not an expensive job nor time consuming for the right person.
 
DrMcNasty

DrMcNasty

New Member
allenp42 said:
As red69 suggested, I would get it welded up and re-tap. Once you use JB Weld, the welder will not be your friend if you decide later to fix it correctly. From what I understand, it makes it very difficult to weld w/o removing all traces of JB. Not an expensive job nor time consuming for the right person.
Click to expand...

Noted. I will be looking for someone to address this locally once I split the case and start the rebuild on the motor.
Thanks for the input everyone.
 
DrMcNasty

DrMcNasty

New Member
CT70-263123 is the frame number, the case on this doesn't match so it is CT70E-262952.

I am going to split the motor as I have to replace the kick start shaft, and I will see if I can have the case repaired unless someone has a case side in good shape, or maybe the matching one? :D
 
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red69

red69

Well-Known Member
Since you are splitting the cases, it's a no-brainer to have it welded by someone competent with MIG or TIG aluminum welding.
 
darrel gunderson

darrel gunderson

Active Member
I have these fixed all the time. The main thing is to have it clean when you take it to have it tig welded. Grind it down carefully and use the flywheel cover as a guide jig when you go to drill and retap the hole. Take your time doing it !
 
DrMcNasty

DrMcNasty

New Member
kirrbby said:
X2^
And since it is the engine that belongs with your frame...it's a very worthwhile, no-brainer.
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I can't be sure of that to be honest as this was a cobbled together barn find, that god only know what they have done to it based on the other things I have seen on this poor bike.
 
DrMcNasty

DrMcNasty

New Member
darrel gunderson said:
I have these fixed all the time. The main thing is to have it clean when you take it to have it tig welded. Grind it down carefully and use the flywheel cover as a guide jig when you go to drill and retap the hole. Take your time doing it !
Click to expand...
Ya once I split the case, I am going to clean it up with a good wash and bring it to an engine shop to see if they can do this for me. I am not taking the risk of doing this on my own. HAHA. That and I don't have the tools for it.
 
Tripod

Tripod

Well-Known Member
Probably one of the easier locations on the case to fix. I would definately fix it and keep the engine with the bike. Farm the job out to someone like Darrel who has had it done and gotten good results.
 
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