Cam Chain Tension Blows out of Cylinder block

Sorry. I knew I had seen a post from you on a different subject, but couldn't remember the details. We've all made mistakes, and all learned from them. As Steve said, repairing stripped threads is just part of working on 40+ year old bikes. I buy helicoil inserts in bulk packages.
The tensioner bolts are 6mx20. I believe they are standard 1.00 pitch thread. Fine would be .75. Look for 6x1.0 inserts for what ever thread repair method you use.

I don't use a special drill bit. The hole is large enough to use the tap. I dip it in grease to lubricate the threads and pick up the filings. If a small amount of filings fall onto the engine, they will be blocked by the strainer and filter. To completely disassemble the engine for two threads is just silly. That's the way I do it, you can do it the way you like.
Steve
BTW, tapping threads mean doing it in stages, not all at once.

It may be possible to drill and tap the threads for a heli-coil with out disassembling the engine, but I would wouldn't do it for another reason. Why did this happen in the first place? I'd at least want to have a look at the roller on the tensioner assembly. Tearing it apart is the only way. Unless you know you over torqued the bolts and stripped the threads, something else caused those threads to rip out. There's only one way to find out.

Just throwing a thought out there.....the amount of force needed to punch out the tensioner would be huge, as you mention there was different tension in the cam chain .....could it be that the chain had somehow jumped off the center sprocket on the crank or wasn't installed correctly? Then when starting the bike that chain could have whipped around or jammed subsequently punching out the tensioner?

I agree with MDZ......I would strip the motor down again to check nothing else went bad in there

To discover this, all that needs to be done is remove the head. You can also look down and see what's happening.
Steve

Update - I pulled off the valve cover and discovered that the valve timing was way off - I screwed up somewhere and the chain must have jumped the sprockets. Anyway, I thought I might as well see if it would run so I reset the valve timing, installed the chain tensioner using longer bolts and she fired up immediately and settled in to a nice smooth idle. I certainly go lucky this time. Thank you to all that helped me out.

Dodged a bullet. Good for you. :woohoo: I'd still Heli Coil them soon.
Steve