!!!
MickM,
Welcome & thanks for your post.
Re g/box spring - The washers seem like a good idea to restrict spring sliding across arm. I didn't feel this movement in itself would be enough to cause spring to break as it's hardened and arm isn't, so it just wears a groove...maybe over v.high miles? we talked about bending tab of spring right around arm to retain. Anyhow I agree it would be good to stop sliding movement & may copy you w/washers when I look in there. Thanks.
Check all nuts & bolts for tightness.
Guzzi can be v mean w grease gun. Esp check needle roller bearing in outside of rear drive hub.
Mine had rear wheel bearing spacer too short, knocked out bearings when axle was tightened.
Make sure there's plenty freeplay in rear brake actuating mech. Some have had binding r brakes.
Some wear bushes of r brake torque arm.
Check tappet clearances not too tight. Dunno where you are but I believe some US bikes ran bad cos of this. Also in US people have had problems with vacuum developing in tank.
G/box commonly weeps. Various possibilities. I suspect seal of rear cover, tho pos lower part of sidecover also. Usually only tiny amount, collects on collector box (of course )
Some have had badly ass'd timing chest gasket blow. Check for weeping around seal, usually by engine mount bolts. Mine was solved just by tightening but if you see a bit of gasket sticking out...
These are occasional problems on some bikes, most are easily fixed. A search will turn up stuff on all these things.
Bike takes a while to run in, about 10K miles motor's really smoothing out. It's a good bike.
KB