Oil burning problem and trying to understand the risk areas

[AUTOMAN]

Ground plug cap or run extra plug on cap, make sure it's grounded!
Do not rev, let it idle with max. intake vacuum.

The best thing you can do is pressurize the intake and watch the bubbles.

 

[Nicko]

Good advice about using a third plug.

I carried out the test yesterday, fired the bike up plenty of smoke on no 1, pulled the plug cap and attached the 3rd plug. Left no 2 running on a fast tickover for about 10 minutes. Removed no1 exhaust and carb. Oil in the exhaust and inlet ports, appeared to be coming from the guide/ head seal on inlet.
Pulled the engine today and removed the head, evidence of oil on the top of the no1 valves.( also to a lesser extent no2 exhaust valve) Head gasket was good, no evidence of cam chain tunnel leakage.
Aiming now to get new guides in the hope this solves it

 

[AUTOMAN]

Good advice about using a third plug.

I carried out the test yesterday, fired the bike up plenty of smoke on no 1, pulled the plug cap and attached the 3rd plug. Left no 2 running on a fast tickover for about 10 minutes. Removed no1 exhaust and carb. Oil in the exhaust and inlet ports, appeared to be coming from the guide/ head seal on inlet.
Pulled the engine today and removed the head, evidence of oil on the top of the no1 valves.( also to a lesser extent no2 exhaust valve) Head gasket was good, no evidence of cam chain tunnel leakage.
Aiming now to get new guides in the hope this solves it

Watch for or inspect for cracks around guide bore.