oceanvibe Posted June 30, 2007 Report Share Posted June 30, 2007 Any ideas as to the cause of the following; Bike runs great when cold, idles just spot on and rides great with smooth power throughout but once it warms up the idle starts to drop off to a point it won't idle even with the screw full in. It will rev up fine but held on a steady rev it is very spluttery and runs a bit rough then when you open it up from there it is bogged down. Any clues ?This is what I've done and the various settings. Main jet 92, pilot jet 35, carb stripped and cleaned several times. Points clean and set at 12, new plug - DR8ES set at 30, got a spark and after the bike has been run and is hot the plug is black but dry. I've also cleaned out the filter and air screw is at 1 1/2 -2 turns out. Point to note is that when I really tighten the carb on the carb slide gets stuck at full open, turn back one of the nuts a half turn it it is fine again! Quote Link to comment Share on other sites More sharing options...
andy m Posted June 30, 2007 Report Share Posted June 30, 2007 Really tightening the carb you are sort of warping the carb body and then it goes back to normal when slackened off slightly. H ave you got the heat shield between carb and head ? As without this you will have similar problems. Quote Link to comment Share on other sites More sharing options...
swooshdave Posted June 30, 2007 Report Share Posted June 30, 2007 (edited) One of the guys I ride with has the same bike and recently put the heat shield on. Apparently (please correct me) the original heat shield was plastic, and of course broke, making them difficult to find. He just took some sheet aluminum (or steel) and fabricated a shield. Seems to have made a huge difference. The shield is just sandwiched between the carb and manifold. He also wrapped the exhaust pipe in header tape, which also seems to have helped. I'm not sure where "Ross-shire" is but I'm guessing that it may not be one of the warmer trials environments so some of these measures may be unnecessary. This particular bike also has a Powrall 150 kit (whatever that is) which may also run warmer. We have suggested instead of the header tape, which is a wee bit unsightly, to have the exhaust pipe ceramic coated. This will have the same impact, although will look better. We are riding this evening and I'll try to get more pictures to post by tomorrow. Edit: Hope this helps. This is a very common problem on the TL125. Edited July 1, 2007 by swooshdave Quote Link to comment Share on other sites More sharing options...
oceanvibe Posted July 1, 2007 Author Report Share Posted July 1, 2007 Thanks for the tips but it still has the original heat sheild on the carb. I had a look a bit deeper into the problem and think I might have found it but please comment on findings. It looks like the crank seal has gone as there is oil all over the flywheel and covering the coils. As the oil heats up it thins allowing it to get throught the seal hence the problem only when hot. I assume that this would cause a bad ciruit resulting in a poor spark which would explain the bike spluttering. With a poor spark the plug would not be firing hot enough to burn the fuel hence the black plug. Does this sound about right and as the coil has been coated in oil should I get a new one or will it be fine once cleaned. All I have to do now is find a new seal !!! Quote Link to comment Share on other sites More sharing options...
andy m Posted July 1, 2007 Report Share Posted July 1, 2007 There is supposed to be oil in there, thats not your problem. 1 Quote Link to comment Share on other sites More sharing options...
brian r Posted July 2, 2007 Report Share Posted July 2, 2007 (edited) Sorry but LOL. Yes, the flywheel runs in oil. Check your valve clearances, try to run on half choke when warm just to see what it does. I think I use a D8ES (non resistor). Sounds like by your jetting it's a 1976. If all else fails, try the earlier jetting of 95 main 38 idle. Plugs .026" Points .014" Valves Intake & Exhaust .002" Edited July 2, 2007 by Brian R Quote Link to comment Share on other sites More sharing options...
oceanvibe Posted July 4, 2007 Author Report Share Posted July 4, 2007 Well yes I have made a *** of myself on the web, (again) after posting the 'leaking seal' I found out it is ment to run wet. Oh well live and learn. Brian, I checked the valves last nite after some brain storming and the exhust valve was cranked right down ! so I am thinking that this might have caused the problem. Reset both to 0.002 and I am heading out the the workshop soon to give it a blast and see. Will let you know. Thanks for the pointers Quote Link to comment Share on other sites More sharing options...
mattylad Posted July 5, 2007 Report Share Posted July 5, 2007 The valve will give you problems if the clearence disappers when hot. It would normally hold the valve open and compression would dissaper. Have you tried running a softer plug. I use an NGK D6ES in mine. The exhaust heat shielding is important, not too difficult to bodge something on for a trial. Also if you wind on the throttle too fast it will cough and run rich, open smoother. Final thought is a resistor plug to blame as I use one without and electronic XL ignition. Quote Link to comment Share on other sites More sharing options...
oceanvibe Posted July 6, 2007 Author Report Share Posted July 6, 2007 Well after I set the valves the bike runs a lot smoother but a bit rattelly (will check the settings again) also dropped the carb needle to the top notch which has really helped. It almost idles now but does not get bogged down. Was trying to geta plug without the R but none of my local dealers have any and only stock the DR8ES-L I believe theL is for a 1/2 heat but which way hotter or colder. Will try again to get a diff. plug but I have just about got it sorted. Tacking it to a trial on Sunday so will post how it goes. Again thanks for all the pointers and keep them coming. Quote Link to comment Share on other sites More sharing options...
swooshdave Posted July 6, 2007 Report Share Posted July 6, 2007 Dealer will typically stock the most popular plugs, and with ten billion to chose from, who can blame them? Once you know the exact plug you want you should order (either special order or internet/mail order) the one you need. Get several, although you shouldn't need too many once it's running correctly. Quote Link to comment Share on other sites More sharing options...
29r Posted July 7, 2007 Report Share Posted July 7, 2007 Might want to check that the advance isn't seized . Adjust the cam chain and then check the timing . The Honda "cough" seemed to be a "design feature ", but properly tuned not a big issue . Quote Link to comment Share on other sites More sharing options...
oceanvibe Posted July 8, 2007 Author Report Share Posted July 8, 2007 Well it went well at the trial today, gave it a good thrashing and for the best part it idled although the plug is still sooting up a bit so probably still a bit rich, might try a smaller main jet. Had a great days trilling until I had a big off going up a rock face and smashed the clutch lever bracket off, oh well more things to buy ! Mattylad was the XL ignition an easy conversion and did you get it off the shelf or from a breakers ? 29r whats the best way to check the timing and how do I check the advanced isn't seized ? Many thanks. Quote Link to comment Share on other sites More sharing options...
29r Posted July 9, 2007 Report Share Posted July 9, 2007 whats the best way to check the timing and how do I check the advanced isn't seized ?Many thanks. Just from memory ( which gets shorter all the time ) You'll find a TDC and a BTD mark on the flywheel , with an adjacent mark on the case somewheres . Tdc should be used setting the valves . BDC is when the points open . You can use a meter or light at rest or a timing light with the motor running . Seems there was a 3rd mark for the advance . The points plate can be rotated to set . Points gap needs to be set 1st . The points cam rotates on a shaft w/ advance wieghts/springs behind the plate . Should be able to reach in there and check that it's free. This Site should be helpful. http://www.kaila.net/tl125/index.html Quote Link to comment Share on other sites More sharing options...
brian r Posted July 9, 2007 Report Share Posted July 9, 2007 Oceanvibe, Does it still have the stock exhaust? Quote Link to comment Share on other sites More sharing options...
oceanvibe Posted July 9, 2007 Author Report Share Posted July 9, 2007 Brian R, No it does not have the stoke exhaust. It came with a bit of a home made thing. The front pipe is standard to just past the back of the engine then there is a can from there about 10" x 3" and that's it. I was not sure if this would alter anything and hoped it wouldn't as it has a sweet tone to it ! Any thoughts on this mod. Changed the condensre tonight and now have a much brighter spark but not run it as it is getting abit late to go bombing about the field so will have a try ma Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.