by Puffs » Sun Jan 06, 2019 5:02 am
Hi tr500,
of course I am not certain your bike has a leaking head gasket. It's a possibility, which could explain what you said. But to be sure you need to investigate it more. For instance: what kind of smoke is it; what does the plug look like; when you parked it & you try starting the bike without spark plug is there anything coming out of the plug hole; any pressure on the cooling system after running (with the engine still cold); do you loose cooling fluid, ...
I have had it once, in a car, resulting in high pressure in the cooling system - a minuscule leak between one of the combustion chambers & the cooling system. I noticed it because the engine started to overheat & loosing cooling fluid, but it started very gradually. But after a while the problems became very serious & quickly after starting I had a lot of pressure on the cooling system.
Easy stuff first: first make sure the engine is not seriously overfilled w/ oil, make sure engine venting is OK, then re-torque the head bolts, to the specified torque. If none of that works, looks like the head has to come off (for either gasket, rings, or guide seals).
Good luck!