Penelephant Posted May 20, 2019 Share Posted May 20, 2019 Hi there, I've been reading lots of posts on here hoping for some help but nothing seems to quite match, anyway... 1987 dt125lc mark3. Was going pretty well, now when it starts up, usually first kick, there seems to be no throttle response except for a backfire. It idles very low, maybe 500rpm. If you slowly move the throttle you can get it to sit at 2000rpm but it still bogs on giving throttle. Randomly if you keep trying the throttle the symptoms seem to disappear. Sometimes if you mess with the throttle cable it seems like it fixes the problem, but it usually comes back again. Very occasionally it will race and you have to shut it down. When its having a good spell it goes great! Things tried so far, crank seals, stator, carb rebuild, plug, also general rewiring including regulator/rectifier and all lighting. If anyone has any tips that would be great. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted May 24, 2019 Moderator Share Posted May 24, 2019 Sounds like fuel flow to me. How is the float height and fuel flow. Link to comment Share on other sites More sharing options...
Penelephant Posted June 4, 2019 Author Share Posted June 4, 2019 Thanks for reply, plenty of fuel flow, float set correctly. Will have another look though. Link to comment Share on other sites More sharing options...
jimmy Posted June 7, 2019 Share Posted June 7, 2019 I had the same issue with a bike I've just bought. It is a 4 stroke but was giving the same symptoms. Thinking it was carburation I bought a full set of needle and main jets. Before I pulled the carbs I replaced the plugs and removed, cleaned and replaced the leads. The bike fired up 2nd kick and I took it a run. Problem solved and it revs cleanly through the rev range. So either a duff plug or loose lead solved it 1 Link to comment Share on other sites More sharing options...
Negotiator Posted February 12, 2022 Share Posted February 12, 2022 On 5/20/2019 at 8:44 PM, Penelephant said: Hi there, I've been reading lots of posts on here hoping for some help but nothing seems to quite match, anyway... 1987 dt125lc mark3. Was going pretty well, now when it starts up, usually first kick, there seems to be no throttle response except for a backfire. It idles very low, maybe 500rpm. If you slowly move the throttle you can get it to sit at 2000rpm but it still bogs on giving throttle. Randomly if you keep trying the throttle the symptoms seem to disappear. Sometimes if you mess with the throttle cable it seems like it fixes the problem, but it usually comes back again. Very occasionally it will race and you have to shut it down. When its having a good spell it goes great! Things tried so far, crank seals, stator, carb rebuild, plug, also general rewiring including regulator/rectifier and all lighting. If anyone has any tips that would be great. I got same bike and same issues, did you sort it I'm about to change stator as that's only part I've not changed. Link to comment Share on other sites More sharing options...
Negotiator Posted October 30, 2022 Share Posted October 30, 2022 I fitted the devmoto combined cdi & power valve controller last month , now absolutely perfect. 1st kick starting every time Link to comment Share on other sites More sharing options...
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