Superfour misfire around 5,500rpm?
Posted: Mon Aug 24, 2009 5:24 pm
Hi all
Wondered whether anyone can help.
I'm at a loss as to what's causing a miss fire on my bike. Doesn't matter if it's in neutral or in any gear, but as soon as the bike reaches 5,500rpm, it miss fires a bit.
It sounds a little like a rev-limiter kind of noise - very constant. It'll clear up around 6.5 / 7 k and then pull to the redline. The bike is extremely smooth revving up to this point with no hint of a fault.
My thoughts were it was electrical related as it's so constant, doesn't matter where I'm riding, how much throttle, etc, it always does it.
The carbs are spotless (ultra sonically cleaned), all the rubbers and gaskets are in tact, I've balanced the carbs, set the mixtures. The bike's had new coils, HT leads, spark plugs, air filter, oil and filter change, etc. Battery holds its charge, it starts on the button with no throttle even after a week of no use and idles very smoothly. Rectifier is working okay too. The bike has got CB1 clocks on, if this could make any difference?
Just running out of ideas for what it can be?
The bike has had a spill on the left hand side as the left hand side engine casing has a few marks on it. The wire from the pulse generator is putting out a decent flow as well.
Any ideas?
Wondered whether anyone can help.
I'm at a loss as to what's causing a miss fire on my bike. Doesn't matter if it's in neutral or in any gear, but as soon as the bike reaches 5,500rpm, it miss fires a bit.
It sounds a little like a rev-limiter kind of noise - very constant. It'll clear up around 6.5 / 7 k and then pull to the redline. The bike is extremely smooth revving up to this point with no hint of a fault.
My thoughts were it was electrical related as it's so constant, doesn't matter where I'm riding, how much throttle, etc, it always does it.
The carbs are spotless (ultra sonically cleaned), all the rubbers and gaskets are in tact, I've balanced the carbs, set the mixtures. The bike's had new coils, HT leads, spark plugs, air filter, oil and filter change, etc. Battery holds its charge, it starts on the button with no throttle even after a week of no use and idles very smoothly. Rectifier is working okay too. The bike has got CB1 clocks on, if this could make any difference?
Just running out of ideas for what it can be?
The bike has had a spill on the left hand side as the left hand side engine casing has a few marks on it. The wire from the pulse generator is putting out a decent flow as well.
Any ideas?