Motorcycle Repair: Mis fire, honda nighthawk 650, cylinder head gasket

Question
Hi Mark,

I bought a 1982 Honda Nighthawk 650 sc - Had 10 k miles on it- Originally had charging system problem and replaced that. I have been riding about 200 miles w the engine oil level higher than it should have been. I dont know if its related but I have a slight leak out of the cylinder head gasket now - but the real problem is that now my bike runs very unevenly and mis fires pretty bad - also lacks the intital grab when I give it throttle - misfiring  is the main problem - I also ran it a few times for a few miles w the choke all the way on by mistake -- Please help. Thanks very very much

Answer
Hi Terry,

I recommend having a local tech inspect the MC for you.

There's too many things goining on with it. I would need to be present and inspect to offer accurate diagnosis.

The oil leak may or may not be attributed to the overfilling of oil. Also, check the air box and air box drain tube for oil. Compression blow-by gasses pressurize the crankcase forcing excessive oil out the crankcase vent.

Running the engine with the choke left on may cause the exhaust pipe to glow dull orange (same with exhaust valves and head). The resulting heat may damage parts. It would need to be checked to know.

Respectfully,
Mark Shively