jeffhj8 Posted October 28, 2014 Share Posted October 28, 2014 Hello all, i am wondering if anyone could help me with my bike that isn't running right. It is a DT 125 LC i believe it is a 1984, i is the unrestricted 10v model. The problems are that when the bike warms up it idles too high, when i turn right it will rev up, and when i am riding it it will rev up and stay like that even if i let go of the throttle, i use the back brake to put it back down again and it seems to be fine after that. All of this seems to be pointing to a short or broken throttle cable but I'm not sure why it would stick high up in revs. If anyone knows or has an idea what this is please reply, and if you need more iinformation dont be afraid to ask. Thanks, Jeff Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 28, 2014 Moderator Share Posted October 28, 2014 Hey jeff, might be throttle cable routing, might be crank seal...might be both? Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 28, 2014 Author Share Posted October 28, 2014 Thanks for the reply i will definitely check the cable tomorrow, but if it was a cranky seal what would i be looking for, and would i have to do an engine tear down? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 29, 2014 Moderator Share Posted October 29, 2014 Thanks for the reply i will definitely check the cable tomorrow, but if it was a cranky seal what would i be looking for, and would i have to do an engine tear down? an easy test of the LH seal is get the motor to where it's racing and shouldnt be spray WD40 through the slots in the magneto flywheel, aim at the seal does the engine speed/noise change much?...if it does the seal needs replacing Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 Thank you, definitely checking tonight. And i will post what happens Link to comment Share on other sites More sharing options...
KevtheRev Posted October 29, 2014 Share Posted October 29, 2014 Good advice above , but my guess is a sticky or badly routed cable , due do the fact that you have this problem on turning the bars . When you are fitting your new cable , oil it well and it'll last years ( make a little funnel from the corner of a plastic bag , pop the cable through the pointy bit and tape it to the cable , put a little oil in your funnel and hang the cable upright somewhere until oil drips from the lower end ) . While you're there check the condition of the carb inlet rubber , if it's cracked or perished it can leak air into the mix causing the engine to race . Best of luck . 1 Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 Good advice above , but my guess is a sticky or badly routed cable , due do the fact that you have this problem on turning the bars . When you are fitting your new cable , oil it well and it'll last years ( make a little funnel from the corner of a plastic bag , pop the cable through the pointy bit and tape it to the cable , put a little oil in your funnel and hang the cable upright somewhere until oil drips from the lower end ) . While you're there check the condition of the carb inlet rubber , if it's cracked or perished it can leak air into the mix causing the engine to race . Best of luck . I will try and work on the cable tonight too. Only problem is that this cable is a two peice so it seperates into two different cables, i dont really have any experience with these and i am not sure where the other cable is even going . I tried to buy a throttle cable and it only came in one of the peices so i didnt even bother. If you guys know what the other part is called please let me know. thanks Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 29, 2014 Moderator Share Posted October 29, 2014 the cable has a 'splitter' so one cable pulls on the carb slide (throttle) and the other regulates the oil pump Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 the cable has a 'splitter' so one cable pulls on the carb slide (throttle) and the other regulates the oil pump That makes sence, so could i just get the cable from the splitter back or would i need the whole assembly to change it out? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 29, 2014 Moderator Share Posted October 29, 2014 I dunno but the original yamaha equipment was probably sold as two seperate items as a guess, maybe the throttle cable for one item and the splitter and two cables and the other? sometimes you can get aftermarket parts but I find them a bit dodgy, sometimes the oil pump cable isnt the right length! anyway until you have some evidence there is something wrong with yours why are you considering changing it? take it off and check it's all moving freely, lubricate it etc Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 I dunno but the original yamaha equipment was probably sold as two seperate items as a guess, maybe the throttle cable for one item and the splitter and two cables and the other? sometimes you can get aftermarket parts but I find them a bit dodgy, sometimes the oil pump cable isnt the right length! anyway until you have some evidence there is something wrong with yours why are you considering changing it? take it off and check it's all moving freely, lubricate it etc That is very true i will check everything, dont want to be too quick to assume. A lot af work to do tonight will post results, thanks guys for the help. Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 I beleive i have found the problem. The throttle cable was not sitting right and it was pulling on the splitter which was pulling the carb cable, after some messing around with it i solved the idling problem !! But sadly if i turn left or right it pulls on the carb cable because there seems to be a break in the line right after the splitter, not exactly sure how i could solve this problem, let me know if anyone has any ideas. And does anyone know what kind of oil this bike take, i looked through the little glass hole and i didnt see any oil at all Lastly i just put a new exhuast on the bike because the other one got split right open after i hit a tree, but anyway the new exhaust is not the stock one so it seems to be more free flowing, but because of this when i shift it will bogg down for a second then work fine, seems to get worse the higher the gear, is it not getting enough gas, would putting a bigger main jet solve this problem, feel free to reply any ideas. thanks again, Jeff Link to comment Share on other sites More sharing options...
blackhat250 Posted October 29, 2014 Share Posted October 29, 2014 Ok" lets start with the oil, its a 2 stroke ,so fill the oil tank,[ semi synth or fully synth] . the sight glass ? is that on casing or oil tank, So you pranged the bike,, could be throttle prob also. Jetting ? gotta do plug chops to see whats needed , that bogging could be too mutch air , this effects running and idle too Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 29, 2014 Author Share Posted October 29, 2014 Im not talking about the two stroke oil its oil injected and it has plenty of oil left there, there is a sight glass by the gears I don't think you put 2 stroke oil in the gears. I have tomorrow off so I will do a plug chop to see, what should I be looking for, coffee brown? Thanks Link to comment Share on other sites More sharing options...
Sacha Posted October 30, 2014 Share Posted October 30, 2014 No, you won't put two stroke in the gearbox. You want a gearbox oil... not car one though. Spark plug help: http://www.aa1car.com/library/reading_spark_plugs.jpg Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 30, 2014 Author Share Posted October 30, 2014 thanks for the help man, ill check the plug tomorrow Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 30, 2014 Moderator Share Posted October 30, 2014 the bike needs to be upright on its wheels for the sight glass Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 30, 2014 Author Share Posted October 30, 2014 I did check it up right on its wheels... can't see any oil but i bought some today and i will put it in. Do you know how i can fix my splitter problem? Thanks Link to comment Share on other sites More sharing options...
Moderator Airhead Posted October 30, 2014 Moderator Share Posted October 30, 2014 dont understand what you were saying? Link to comment Share on other sites More sharing options...
jeffhj8 Posted October 30, 2014 Author Share Posted October 30, 2014 sorry worded it wrong, but anyway i have fixed all of the throttle problems, it idles a bit low but its fine, the throttle doesnt stick anymore and i can turn left or right without anything happening to the throttle. I beleive all these problems are because the throttle cable was to short but i have it set up just right where it works fine. I do still have the problem with the bogging down every time i shift though and i did the plug chop and it looks fine to me and im not sure how to post a picture off my computer. Any ideas though on the bogging? Link to comment Share on other sites More sharing options...
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