Chainsaw Repair

i was wondering the same thing about the ports at the bottom of the cylinder

I think it may work for you, with some mods. The 064 use 5mm cylinder bolts and the 660 uses 6mm bolts.  As long as the cylinder clears the case you should be ok if it won't you will have to file,grind to remove the material to make it fit. The piston pin size is the same and the stroke of the crank is also the same so all good there. Hope this helps.

thanks guys, the only problem i had was the crank out of the ms660 rubbed a little on the bottom of the connecting rod when the piston stroke was all the way down, so i shaved it a little now its good to go.wanted the ms660 crank for the plastic flywheel little lighter and better throttle response.thanks for the help

Thats interesting, as the flywheel from a 10mm 044 (which is heavier) has shown to give better performance than the lighter 12mm 044 flywheel, when installed on a 12mm 044

Have you tried the lighter flywheel already ?

no i just assumed because it was lighter so i figured there would be less weight for the engine to turn,i wish i would of tried the other one before i changed it now

the ms660 is done going to put it on ebay and buy a new ms261c