Symptoms are: It will sometimes start, will run for a short time then cut out and the plug will be fouled.
Carb settings are to the book, filled with new fuel, timing spot on, all electrical connections good, choke is shutting off, good compression, tried several plugs, tried a different coil. You name it I have probably checked it, oh yes and the silencer is not blocked, nor is the air intake.
Aparrently there is a small O ring seal between the crank cases that can let gerbox oil into the crank, so I drained the gearbox and fired it up, same result fouled plug so cant be that seal.
The only thing I have not changed is the air flter, which looks clear enough but according to what looks like a date code might be 19 years old.
I have just about out of patience with this thing, I have never had a bike give me such problems and I have had some right dogs in the past, this one is rapidly rising to the top of the sh*t pile.
If it goes on E-Bay I'll have to sell at a loss, but to be honest I can do without the hassle it is giving me.