QuestionMy bike has been in various shops for almost a year trying to get to the
bottom of this problem. I keep getting fouled plugs on both sides equally
after running the bike about 10-15 miles. I've had it tuned up (points
checked), new coils, new starter and wiring to the starter (since it's in the
same system as the coils), and the carbs adjusted (leaned out) but nothing
has worked. What would you suggest as far at the next step to take? Is it
something more sinister like bad rings? Is there a way to diagnose other
problems? Thanks in advance! Ray
AnswerRay,
have you checked the ignition advance unit?
If the timing is late the fuel may not have enough
time to burn fully, hence the dry fouling.
is it dry carbon fouling or wet oily fouling?
If it's dry, it is the fuel mixture, or plugged exhaust
system.
if it's wet it is fuel flooding or oil fouling.
Is the choke okay?
Is your engine breather running into the air
filter box, this can suck oily air into the intake.
It may be possible to have bad oil rings
and good compression rings I suppose,
but not common. Valve seals, maybe, but
most likely leaking rings. How is the compression?
Have you tried NGK platinum tipped plugs?
They have the small electrode and are resistant
to fouling. Oil fouling can only come from the
engine, try some "seafoam" or similar in the fuel to
possibly free stuck rings. They may be carboned
up and stuck. Last resort, rebuild the top end.
