Chainsaw Repair

The engine mounting hardware is just dumb on these - must have assigned that to some engineer fresh out of school.  While it's nice that the mounting bolts don't hold the clamshell together, there is no locking hardware on the mounting bolts.  They are those tri-lobe thread forming screws with a large diameter head, but the head binds to a shoulder bushing that is free to rotate, so it does and the screws back out.  LocTite doesn't work too well because of the tri-lobe thread profile - there isn't thread contact all the way around. 

These 46cc engines shake like heck, I suspect because they didn't change the crank and counterweights when they went to larger displacements.  Everything that isn't held down well is coming off.  When mine came loose it wrecked the oil pump.  I used 5mm helicoils in the mounting bolt holes and cap screws with LocTite - it's been solid since.