Cutting back ?
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@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 -
@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
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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
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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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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
@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
@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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@dtlee Ignition coil should have an earth, voltage rectifier should have one and the battery terminal is earthed.
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Is there an easy way to temporarily disable the oil pump? I just want to check if it’s not packing up? It all looks correct but my plug is still oily and the bikes still cutting back at around 6-7krpm. I’ve checked the power valve isn’t the problem by pinning it open, took it for a ride and was still having the same issue. I was thinking of trying to pre mix the fuel and disable to oil pump to work out of its this causing the problem.
I’m running out of ideas with it. Failing this I guess it’s the ignition breaking down.
( I have cleaned out the carb, fuel line and the tank also and now put back on the original exhaust )
Any ideas I’d be grateful
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Is there an easy way to temporarily disable the oil pump? I just want to check if it’s not packing up? It all looks correct but my plug is still oily and the bikes still cutting back at around 6-7krpm. I’ve checked the power valve isn’t the problem by pinning it open, took it for a ride and was still having the same issue. I was thinking of trying to pre mix the fuel and disable to oil pump to work out of its this causing the problem.
I’m running out of ideas with it. Failing this I guess it’s the ignition breaking down.
( I have cleaned out the carb, fuel line and the tank also and now put back on the original exhaust )
Any ideas I’d be grateful
I stuck the outlet (skinny) pipe into the inlet (fatter) pipe to cause a continuous loop. Been like that and ok for a 1000 miles, just don’t forget to block the inlet manifold oil inlet. I just cut and folded over some pipe, then zip tied it.
It stopped messing it’s pants all over the number plate now as well since I’ve been on pre mix...I can’t remember what I’ve asked you before, but t did you do anything to the bike before it started happening? Even if it was a month before or seems irrelevant?...
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I stuck the outlet (skinny) pipe into the inlet (fatter) pipe to cause a continuous loop. Been like that and ok for a 1000 miles, just don’t forget to block the inlet manifold oil inlet. I just cut and folded over some pipe, then zip tied it.
It stopped messing it’s pants all over the number plate now as well since I’ve been on pre mix...I can’t remember what I’ve asked you before, but t did you do anything to the bike before it started happening? Even if it was a month before or seems irrelevant?...
Did you remove and clean the outside of the needle valve tube? You tap it in and up through the throttle valve body to remove it. Mine was cemented up with micro fine sand stuff...
P.S. Did this come on all of a sudden or gradually get worse?...
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Did you remove and clean the outside of the needle valve tube? You tap it in and up through the throttle valve body to remove it. Mine was cemented up with micro fine sand stuff...
P.S. Did this come on all of a sudden or gradually get worse?...
@spookdog It’s progressively got worse I think. All I have done is moved the read switch, put a full dep on and turned the power valve so it works. It used to do it after 40mins of riding but not it seem to do it constantly. Won’t got about 6-7krpm it just cuts back. I might try what you done with the oil pump just to rule another thing out. It’s massive annoying specially as I don’t a 100 mile long distance trial today and had to put up with that all day.
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Did you remove and clean the outside of the needle valve tube? You tap it in and up through the throttle valve body to remove it. Mine was cemented up with micro fine sand stuff...
P.S. Did this come on all of a sudden or gradually get worse?...
