Topic: Need to Replace Seals? Which?

[InTheStreet]

I just picked up another 550, '78 this time.  It came with two engines.  The original was running with 31,XXX miles.  The other engine is prettier and only has 5k on it, but there is no telling how long it has been sitting.  Rebuilding the carbs is a given.

I plan on using the one with 5k.  What do I need to replace to have a clean running engine before I put it in the frame?
Seals?
Gaskets?
Clutch discs?
O-rings?
Obviously I don't want to disturb anything that does not need to be.  Any help will be appreciated.

[calj737]

Honestly, perhaps nothing. You should at a minimum drain the oil and spray penetrating oil in the cylinders (remove spark plugs) and determine if it will turn over.

There's a recent post about minimal wiring necessary to fire an engine out of a bike. You could certainly do that to determine the health overall before installing or tearing into it. This won't analyze the clutch, but with only 5k miles, I shouldn't expect a problem there.

If the engine has been stored with oil in it, the critical seals should still be good, but only a good long run at full operating temp will identify a leak. Even then, it may self-heal after some run time and rehydrating.

Hope that helps

[InTheStreet]

Thanks for the quick reply.  The engine does turn.  The oil was mostly drained from the engine some time ago.  Will sitting without being soaked in oil kill the friction discs?

[calj737]

Shouldn't, but there could be some issues until they rehydrate.  Fire it up and warm the engine up really well. Get some oil circulating in there. I might add Marvel to the engine oil to aide in relubricating. Then plan to drain the oil after a good hour or two of running. Check the oil pan for any dangerous indicators, then refill.

Won't know about the clutch until you get a cable on it and run it through the gears. But even that should come back around. Worst case, you can drain the basket (separate drain plug under right side cover) and replace the discs with engine in the bike later.