I meant with the cylinder off. On my second kit the counter balance on the crank slightly hit the bottom of the piston at the bottom of the stroke.
I had a 54mm like that. A little die grinder (or file work) will fix it. That particular saw has a solid year of use on it from a young fellow using it to block firewood.
I have never had a keyway shear. I put my flywheel nut on with a "butter fly" air wrench. I just let it "rattle" for a second or two. Usually enough. Have no idea what the torque actually is.
And I always use an OEM decomp now. I would like to plug them, just with my 56mm I can't pull it over fast enough when its cold without the decomp.
It's had to have been said a few times:
Use the following OEM parts:
Chain Adjuster Assembly, ALL of it.
Clutch Drum (Oregon or something better than AM)
OEM Rubber Seals for Gas & Oil caps
I use OEM pulse lines
Also swapped to a Walbro on my 56mm versions.
Also with the 56mm ALWAYS use a gasket. Also I have had to "trim" the ID of those base gaskets on one as the ID was too small. Those 56mm cylinders are going to have a little free port issue, like .010. That's because a 56mm piston won't fit down into the case so they just made them shorter. You take out the gasket that's now a .030 free port and will begin to matter. And I always use my tried and true three bond to augment the base gasket. Haven't had any leak issue yet. But also haven't sheared any key ways yet! Maybe things have changed since last year.