Rear engine mount

[Lee Brown]

Hey Pog members,does anybody have the proper way to set up the tolerances between rear motor,spacer,PN-55.03.052.00 and frame when installing rear motor mount bolt, and spacer on HS and MC5 Ive seen several bikes were the motor is vibrating around in the frame,rear motor mount bolts break off, and even causing rear motor cases to crack on left side,are there different size spacers between engine and frame,maybe swingarm and frame tolerances are off,what give in ths area thx......

x

[454MRW]

I rarely see this happen on a rear motor mount, but I have seen some vibration wear that made the threaded insert loose in the case, and a lot of front motor mount bosses wallowed out or damaged from vibration. Be sure to tighten the rear engine mount before you tighten down the pinch/locking bolt for the swingarm bolt, as this pulls the frame together against the engine, spacer, and swingarm nuts, which should have very slight clearance to assure that they are not keeping the frame apart from fully allowing the rear engine mount to be tight.
I usually turn the swingarm nuts inward with 2 thin modified 24mm wrenches so they are loose, and after tightening the engine mount and swingarm bolt pinch/locking bolt, back the nuts back out to assure that they don't interfere with the process.
Checking the tightness of all motor mount bolts is a routine maintenance must that is often put off or overlooked, and should be done frequently. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R