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. 

Mine shakes quit a bit when idling but smooth's out well at cutting speed.  I wonder what the nominal engine compression on these 46cc powerheads runs at?

The A/V is good and fools you - stick your thumb down on the top cover while you're cutting and you feel what the the other part of the saw is doing!

More 46cc stuff experimenting with changing from .325" setup to 3/8-.50" bar and chain.  First used 72 DL bar and chain but after test cuts thinking the small clutch diameter is a limiting factor more than power available.  Decided to go with 18" and 68 DL bar and chain setup and have not tested with it yet but am confident for firewood cutting.  Reason behind this is I am not especially fond of .325" chains for firewood cutting, seems like they go dull way too quickly and I have extra lying around on the 3/8" stuff I could be using on this saw.