Stripped Left hand lower engine mount please help!

Hi all,

I recently got hold of some chrome engine guards for my 1977 z1000. I read that you can install them by removing and reinstalling one engine mounting bolt at a time.
I started by trying to remove the lower left hand engine mounting. The bolt came loose and I managed to back it out about 10mm but as I was turning I didn’t realise but it was no longer backing out of the hole and just spinning. 

The bolt won’t come out but can be turned back in but will not tighten so I guess I’ve stripped the aluminium thread.

Question is, has anyone else stripped that thread and successfully done a thread repair without dropping the engine from frame?

Also, did I stuff up by not supporting the engine with a jack? I would have thought the other five bolts would have been enough not to need that. 

Would you mind sharing a picture of your engine mounts?  Maybe you could dremel/grinder or chisel out the engine mount nut. 

None of the engine mounts on 73-80 Z1/Kz900-1000 engines are threaded.  The lower left and lower right bolts thread into a “teardrop” nut the resides inside a cavity cast into the lower crankcase half.  The nut may have dropped out on you or fell out long ago although, highly unlikely.


Later, Doug

   We have mini case guards on all our Z1's. We've never stripped threads on the teardrop nuts.

But...

   The lower case guard brackets are thick enough to require slightly longer bolts when mounting case guards to ensure all threads are engaged in the teardrop, but not so long as to contact the teardrop cavity's other side. 

   The ones pictured look to have collars on the lower mounts.  A standard bolt will likely engage few threads in the teardrop.

  One must be very careful when fitting longer bolts on the lower mounts, as a bolt too long will contact the solid side of teardrop's cavity, giving false sense of being tight.  Or, worst case, force it's way well into the case.   There were pics posted here some time ago of exactly that happening.  That's a bad day in the making.

  The cavity in which the teardrop lives is only slightly wider than the teardrop is thick.  If a longer bolt is used, monitor clearance visually from underneath using a mirror.  Use washers as shim, as needed, to prevent the end of the bolt from contacting the case inside the teardrop's cavity.

Good Ridin'
slmjim & Z1BEBE