Re: 115 mer crank shaft end play
There should little to no visible side-to-side play on crankshaft bearings. The free-end play (axial thrust) is specified as max of .012" but I prefer when rebuilding to adjust via shimming to around .004-.006". No sense starting out at the maximum allowable spec.
At any rate, visible side-to-side slop when you're wiggling the flywheel is a good indicator that the upper ball bearing (in the end cap) is quite worn. Ball bearings run tight clearances in that direction, so to see one sloppy means the balls & race are pretty bad.
You could remove the flywheel and pull the bearing end cap to inspect, but it's too tight to get a bearing puller in there. You'd have to remove the powerhead, split the crankcase halves then pull the rotating assembly at least part way out to gain access to the bearing.
At that point you may as well pull everything out and check for cylinder/piston scuffing & wear, renew rings, seals, bearings as applicable. If the upper bearing is that bad, it's highly likely the lower bearing is in worse shape.
BTW you don't say what motor or ign you have but failure to rev can also be caused by a bad stator (on "ADI" ignition systems only). If you do have a motor with ADI, check the Hi-Speed windings' resistance and if they are out of spec, the stator is bad.
BTW it's highly unlikely that having side-play in the crank bearing would cause a non-revving condition, unless it's an indication of a very badly worn out motor. So, unfortunately, you may have more than just a running problem coming your way.
HTH & G'luck.........ed
