Cutting back ?
Have you checked the power jet pipe? It’s the plastic pipe that connects the bowl to the carb body. If that’s leaky or cracked it won’t be pulling any fuel into the power jet at full throttle...
@spookdog cheers I’ll have a look at that too
I’ve checked the power jet pipe and that was clear and drained the carb and put new fuel in and it was still cutting back at higher RPM. I checked the HT lead and that seemed good so I changed the spark plug and I think that has sorted it although I’m yet to take the bike out properly. What I did notice is that the spark I took out was oily so I’m guessing that’s stopping it from sparking properly which could of caused it?? Obviously changing the plug now will only temporarily fix it until this one gets oily. Where should I be looking l next to sort out the lean running issue. I did notice my number plate was covered in splattered oil from the exhaust, ! which I’m guessing isn't healthy ??
Any help appreciated
Calum last edited by
@dtlee Examine the oil pump settings, make sure they are correct.
It might be the right hand crank shaft seal has gone bad, seaping Gearbox oil into the combustion chamber. Which I'm afraid, is a engine out cases split jobby to fix, since access to it can only be got at from behind the main bearings.
@calum cheers will have a look into it
the power valve pipe needs to be air-leak free. If it looks old and dry or cracked, replace it..
My number plate is dripping with shitty old 2/ from the silencer. It’s just the way it is with 2/‘s. Even if you pre-mix your fuel & oil...
Wet plug could just as easily be to much fuel or the ignition breaking down. It also depends if the engine was up to temperature? Cold engine makes for wet plug, in my experience...
DTlee last edited by DTlee
@spookdog thanks for your advice. I moved the Reed switch out from the Rev counter a long time ago and it’s always been fine. The problems I’m having now are more recent. Will have a look into the ignition and carb jets and see how I get on cheers
That’s an electronic rev limiter isn’t it? I think the 1997 onwards bikes have them? Y/N? Maybe that connectors the problem?
I have an 1988 onwards wiring loom/CDI. So I wasn’t sure what you meant
A little back history is really helpful. When (& if!) it last ran proper, any changes you’ve made, Bada bada, bing bing! You get the pic? Helps diagnose problematic changes...
Carb jets won’t be the problem, they don’t change from right to wrong. Air leaks will, as will crank seals. I doubt that it’s that though. Not if the bearings aren’t noisy...
Seriously, I’d check the rev limiter mod
It sounds like it could be breaking down, if that’s possible...
Sorry, couldn’t see or reach to type in my last post on my phone screen...
@spookdog haha cheers will investigate a bit more and update