Saving Old Seagulls

I got given a Century Seagull recently. Initially, it ran OK, for ~ 15 mins. THen there was a bit of a clunk, and it started vibrating ++, and lost power. Any ideas as to what is going on inside. I wonder about bearings. THere is a bit of vertical play witht eh flywheel, (which I assume is normal), but no real side to side play.
Hume

Progress Report:
I pulled the power unit off this morning, and the cylinder and crank seem pretty good, so I have left that intact. THe flywheel spins beuatifully, and there is no side to side play.
Instead, the gear box is decidedly crunchy!!
Pulled the gear box apart, and the pinion anad crown gears are very worn. I have ust orderd repacement from Sydney, so fingers crossed, that is the cause of the vibrations.
Hume

good you found replacement

Hume where are you in Brisbane as I know an excellent source for seagull parts on the north side
Chris

I actually live in Toowoomba, but am in Brissy a lot. I would love to know of a supplier/ seagull person in Bbne.
Hume

hello Hume
have sent you a private message with the contact details
Chris