Dtr 125 choke and Rev problem. Looks like it works reversed way!



  • Hi
    Got myself a dtr 125 2007, rebuilded engine, new piston kit, gaskets, bearings. Got a carburetor cleaned, new reeds and can't figure out why it revs as crazy.
    When choke is on its all normal, bike goes steadish about 1200-1400 revs. Get a choke off and it's goes as high as 2300. After 10 minutes coolant light goes on. Airways have no leaks, coolant level stays same and also can't see any leaks. Please help, this bike is doing my head in.



  • @pete_dtr Moved to the correct section.

    Hello there, it's always a good idea to introduce yourself prior to asking for help, just out of common courtesy

    Is the bike overheating is that why the light goes on. What's the colour of the spark plug.



  • Aye Calum, I'm Pete and I am new to 2stroke. Spark plug is brand new, maybe an hour on the run. It's black and oily.



  • Check the thermostat. It could be duff and not opening.

    The way to test that is to put it in some water and heat the water, after a certain temperature it'll pop open.

    If it doesn't then that'll be why it's over heating.

    The coolant system should be properly bled as well.



  • Not sure if this well help much but I had a similar problem with my 2000 dtr, would rev normally with choke on but when you take it off after it has warmed up it would rev too high and I had a really tough time getting it down. Took the carb apart and found it was filled with crap, all blocked and somehow had a bee in it? No clue how it got there but it did somehow. Anyway, cleaned it up, stuck it back in and problem sorted. Did you clean the carb yourself?



  • HIgh revs at idle is almost always some sort of lean condition, often false air. It could be crank seals. Have you adjusted the carb in any way, or are all the jets ect stock, and the needle in stock position?



  • @Minia hi, thanks for replying. Just back from sea, cleaned carburetor, every chanell hose and pipe. Checked jets and float position and it's all fine. Put it back on and now it don't want to start. It starts for 5 seconds then just dies and refuses to start again. Air mix screw is 1and 1/2 turn out and Rev screw is pretty much in. No air leaks. Recently changed crank seals. Seams to me it runs really rich and flods engine.



  • @Jens-Eskildsen hi, thanks for replying. Just cleaned up the carb, checked everything, jets are fine and standard 17.5 and 250. Just changed crank seals so no leaks there. Tryed that today and bike ain't start. Starts for 5seconds than just floods and dies and refuses to start again.



  • @Calum Aye Calum, cheers, I did bled system and issue is sorted. Water pump was airlocked, that's all. The thermostat should fully open about 78 degrees.