Cutting back ?
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wrote on 1 May 2021, 18:16 last edited by
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
Thanks
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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
Thanks
wrote on 1 May 2021, 20:05 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.
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@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.
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wrote on 2 May 2021, 20:14 last edited by SpookDog 5 Feb 2021, 21:16
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...
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Ah okay. When I said full power I mean I have moved the Reed switch away and the power Valve is working properly. It’s a french import with the better cdi from what I can remember researching. It’s was revving perfectly in the past, right up to 11000rpm. It just seems to be at full throttle between 8-9000 RPM. Maybe I’ll give the card a clean first and go from there.
Thanks
wrote on 2 May 2021, 20:19 last edited by SpookDog 5 Feb 2021, 21:21@dtlee said in Cutting back ?:
Ah okay. When I said full power I mean I have moved the Reed switch away
What do you mean by that? Has the problem happened since this or just lately all of a sudden?...
Cheers bud -
@dtlee said in Cutting back ?:
Ah okay. When I said full power I mean I have moved the Reed switch away
What do you mean by that? Has the problem happened since this or just lately all of a sudden?...
Cheers budwrote on 2 May 2021, 20:41 last edited by DTlee 5 Feb 2021, 21:48@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
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@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
wrote on 3 May 2021, 17:17 last edited by SpookDog 5 Mar 2021, 18:23That’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
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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 meantA 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
wrote on 3 May 2021, 17:25 last edited by SpookDog 5 Mar 2021, 18:26It 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...
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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...
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wrote on 8 Sept 2021, 21:17 last edited by
Is there a way to check if the ignition is breaking down? I’ve checked everything mentioned above and cleaned the carb out etc. But still the book it’s cutting back intermittently at about 8000rpm. Before I split the casing and check seals I want to make sure I’ve checked everything else.
It seems to run perfect for about 20mins riding the then seems to start and progressively gets worse. Could this be as it warms up the ignition is failing
TIA
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Is there a way to check if the ignition is breaking down? I’ve checked everything mentioned above and cleaned the carb out etc. But still the book it’s cutting back intermittently at about 8000rpm. Before I split the casing and check seals I want to make sure I’ve checked everything else.
It seems to run perfect for about 20mins riding the then seems to start and progressively gets worse. Could this be as it warms up the ignition is failing
TIA
wrote on 9 Sept 2021, 03:16 last edited by declan 9 Sept 2021, 05:07@dtlee as electronics warm up the resistance changes I'd hazard a guess with the problems your having you might have a faulty ignition coil as the coil warms up it might be out of spec this is easily checked with a multimeter via the Haynes manual, my bike cuts back at the same rpm never been able to remedy it- edit when I say ignition coil I mean the physical coil on the stator not the ht coil although that also can be an issue when it warms up
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@dtlee as electronics warm up the resistance changes I'd hazard a guess with the problems your having you might have a faulty ignition coil as the coil warms up it might be out of spec this is easily checked with a multimeter via the Haynes manual, my bike cuts back at the same rpm never been able to remedy it- edit when I say ignition coil I mean the physical coil on the stator not the ht coil although that also can be an issue when it warms up
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Is there a way to check if the ignition is breaking down? I’ve checked everything mentioned above and cleaned the carb out etc. But still the book it’s cutting back intermittently at about 8000rpm. Before I split the casing and check seals I want to make sure I’ve checked everything else.
It seems to run perfect for about 20mins riding the then seems to start and progressively gets worse. Could this be as it warms up the ignition is failing
TIA
wrote on 9 Sept 2021, 15:33 last edited by@dtlee I had this recently on my DT when I replaced the perfectly working coil for a Chinese "Racing" coil. It worked fine for the first 100 miles then just refused to rev properly.
Getting a nice genuine coil seemed to have fixed it.
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@dtlee I had this recently on my DT when I replaced the perfectly working coil for a Chinese "Racing" coil. It worked fine for the first 100 miles then just refused to rev properly.
Getting a nice genuine coil seemed to have fixed it.
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@dtlee yeah gonna try switching my main jet to a 240 see if that does anything gonna be a whole though as the engine is under the knife
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@declan I was thinking about jetting too but don’t want to mess with it too much as It used to ride fine before so I don’t think it will help me out
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wrote on 11 Sept 2021, 08:54 last edited by
@declan just another though, I should probably checked that everything is earthed properly and that’s it’s not just something stupid like that? Do you know where the earthing point are on the bike. I had a quick look but couldn’t see anything obvious?
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@dtlee Ignition coil should have an earth, voltage rectifier should have one and the battery terminal is earthed.
