NC30 Misfire / running on 3
Posted: Thu Sep 05, 2019 2:18 pm
Hi All,
Its been a while, but I'm looking for some reassurance that I'm heading in the right direction.
I've had an issue with my NC for a few months now thats occurring more and more frequently.
Essentially the bike will drop on to 3 cylinders under load, then pick back up again. Usually fine at idle, unless its cold out. She runs a TSR 3/4 system, when I first bought it I went 118 / 120 jets, shimmed the needles as Graham's guide etc etc. All ran fine.
The bike had been sat unused for a while due to moving house, and initially this only happened infrequently, but its been gradually more pronounced.
I initially stripped the carbs, cleaned them out, made sure everything was ok there. I then suspected duff fuel, as I refilled after with higher octane and it helped matters. Its now happening consistently when its cold out, and under throttle load until the bike gets warm.
I put a new Vac tube on 18 months or so back - the thick wall stuff from GF - so it shouldnt be that.
I'm suspecting spark plugs, leads or coils. Sparks are going to be my first guess, as I have a new set - even though they're a pain in the ass to change from memory.
Its been a while, but I'm looking for some reassurance that I'm heading in the right direction.
I've had an issue with my NC for a few months now thats occurring more and more frequently.
Essentially the bike will drop on to 3 cylinders under load, then pick back up again. Usually fine at idle, unless its cold out. She runs a TSR 3/4 system, when I first bought it I went 118 / 120 jets, shimmed the needles as Graham's guide etc etc. All ran fine.
The bike had been sat unused for a while due to moving house, and initially this only happened infrequently, but its been gradually more pronounced.
I initially stripped the carbs, cleaned them out, made sure everything was ok there. I then suspected duff fuel, as I refilled after with higher octane and it helped matters. Its now happening consistently when its cold out, and under throttle load until the bike gets warm.
I put a new Vac tube on 18 months or so back - the thick wall stuff from GF - so it shouldnt be that.
I'm suspecting spark plugs, leads or coils. Sparks are going to be my first guess, as I have a new set - even though they're a pain in the ass to change from memory.