YAMAHA21 Posted January 15, 2017 Share Posted January 15, 2017 Within the last couple of weeks my dt125 has started stuttering around when you reach the powerband. It also jerks forward a bit while it stutters. I haven't changed anything on the bike recently so I don't know why this has stared happening. Just yesterday I took the carb off and cleaned it out as I thought the main jet might be getting blocked but that didn't solve the problem. I have also tried multiple spark plugs. Some things I have noticed: it doesn't do it nearly as bad if at all when the bike hasn't yet reached full temperature, so for the first minute after pulling away the bike feels so much better. I've got some sound clips where can hear the problem. Clip1 Clip2 Clip3. Anybody have any idea what the problem is? It's really annoying because you're unable to ride the bike at a decent speed as it wont rev past the point where it stutters. Cheers Link to comment Share on other sites More sharing options...
Moderator Cynic Posted January 15, 2017 Moderator Share Posted January 15, 2017 Plug colour? Good spark? Mileage? How long has the top end been on? Checked ALL the electrical connections for the ig, including the kill switch on the bars and the engine earth as well as the mag outputs. Filter clean Reeds in place and good condition Exhaust tight Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 15, 2017 Author Share Posted January 15, 2017 15 minutes ago, Cynic said: Plug colour? Good spark? Mileage? How long has the top end been on? Checked ALL the electrical connections for the ig, including the kill switch on the bars and the engine earth as well as the mag outputs. Filter clean Reeds in place and good condition Exhaust tight I can answer some of these now. The plug is a light brown colour, I think it's okay. As far as I know the spark is decent but I'll check properly soon. The bike has just broke 10k miles but it's only done at most 2000 miles since the top end was rebuilt. I checked the filter fairly recently and it was clean but I'll check that again. I'm also pretty sure the reeds and exhaust are okay but I'll make sure. Link to comment Share on other sites More sharing options...
finnerz89 Posted January 15, 2017 Share Posted January 15, 2017 How long has it been doing it? Have you put fresh fuel in it since? Sent from my E6553 using Tapatalk Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 15, 2017 Author Share Posted January 15, 2017 1 hour ago, finnerz89 said: How long has it been doing it? Have you put fresh fuel in it since? Sent from my E6553 using Tapatalk It started a few days after Christmas. I've gone through a few tanks worth of petrol since it started. Link to comment Share on other sites More sharing options...
finnerz89 Posted January 15, 2017 Share Posted January 15, 2017 What RPM does it start doing it? And what year is your bike? Sent from my E6553 using Tapatalk Link to comment Share on other sites More sharing options...
slice Posted January 16, 2017 Share Posted January 16, 2017 It sounds like fuel or spark problems, if you have already checked the carb then my next thing would be to check the HT lead and plug cap, it's usually the small things that go first and a new cap will only cost a couple of quid. Also make sure the HT lead is not trapped or rubbed through anywhere that it can spark across on the frame or something, does sound like a misfire to me tho. Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 16, 2017 Author Share Posted January 16, 2017 10 hours ago, finnerz89 said: What RPM does it start doing it? And what year is your bike? Sent from my E6553 using Tapatalk It starts at around 7k rpm and its a 2007 dt125x. Link to comment Share on other sites More sharing options...
finnerz89 Posted January 16, 2017 Share Posted January 16, 2017 Is your bike derestricted? That's when the cdi starts to retard the powervalve to limit the power on restricted bikes Sent from my E6553 using Tapatalk Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 16, 2017 Author Share Posted January 16, 2017 5 hours ago, finnerz89 said: Is your bike derestricted? That's when the cdi starts to retard the powervalve to limit the power on restricted bikes Sent from my E6553 using Tapatalk No Iv'e derestricted it and im pretty sure thats not the problem. I remember what it felt like riding it restricted and this is differrent. It wants to rev more but it just cant whereas when it was restricted the bike felt like it was redlining at 7k rpm. Link to comment Share on other sites More sharing options...
finnerz89 Posted January 16, 2017 Share Posted January 16, 2017 Just sounded similar to mine when it had the rev limiter on. Where did you earth the cable behind the clocks? I'd double check it's all good. I'm also assuming you have an aftermarket rev counter then? Sent from my E6553 using Tapatalk Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 16, 2017 Author Share Posted January 16, 2017 2 hours ago, finnerz89 said: Just sounded similar to mine when it had the rev limiter on. Where did you earth the cable behind the clocks? I'd double check it's all good. I'm also assuming you have an aftermarket rev counter then? Sent from my E6553 using Tapatalk I did have but got rid of it about a month ago. Actually I'll make sure to check the connectors on the coil because that's where I connected the tacho. I earthed the cable directly to the frame under the bolt for the radiator bracket. Link to comment Share on other sites More sharing options...
nigel smith Posted January 18, 2017 Share Posted January 18, 2017 hi there i had the same problem on mine and it was a bad earth from the dash wire where it had been earthed to the frame. 3 Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 19, 2017 Author Share Posted January 19, 2017 I figured out what it was. It was the connector on the coil which I used as the feed for the tacho. The connector was loose so I just squashed it a bit and problem solved. 1 Link to comment Share on other sites More sharing options...
finnerz89 Posted January 19, 2017 Share Posted January 19, 2017 Nice work! Sent from my E6553 using Tapatalk Link to comment Share on other sites More sharing options...
slice Posted January 19, 2017 Share Posted January 19, 2017 Err, thought I said that? 1 Link to comment Share on other sites More sharing options...
YAMAHA21 Posted January 19, 2017 Author Share Posted January 19, 2017 5 hours ago, slice said: Err, thought I said that? I do owe you some credit mate, cheers 1 Link to comment Share on other sites More sharing options...
Moderator Cynic Posted January 20, 2017 Moderator Share Posted January 20, 2017 "Cough, cough". Post #2 Link to comment Share on other sites More sharing options...
mcferreira100 Posted June 16, 2017 Share Posted June 16, 2017 I have had a TZR250 refusing to run on both cylinders..replacing a plug cap sorted it Link to comment Share on other sites More sharing options...
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