1987 Suzuki GS450L oil leak

My recently purchased 1987 Suzuki GS450L has an oli leak it seems at
the head gasket on one cylinder. The bike still runs but on my last
ride it took a mile or so before that cylinder would fire. The blue
exhaust pipe would seem to indicate that cylinder is running hotter
than the other. This bike has only done 5k miles. Any ideas as to
what the problem could be - blown head gasket or is there an oil ring
there that could be broken?

 

Thanks, tomorrow I'll look for the B12, kiwi

 

Found the B12 and have run a can through the tank, the problem
persists as does the oil leak. Does anyone know whether I have to
remove the engine from the frame to remove the head and replace the o-
ring. kiwi

 

You don't.