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smokey bike on start up

Discussion in 'Technical and Troubleshooting Torque' started by davway, Aug 24, 2007.

  1. bike has been sitting since the end of 05.
    i have got it running again but it is smokey on start up when it is cold.
    when its warm, it is fine.
    the recommended oil is 10W 40, should i change the oil to say 15W or 20W 40 (or even 50) so it is thicker?
    is it likely that it is only smokey because it has sat for so long and needs "wearing in" again (and a good highway blowout)?
    could it be the valves (or valve seats) that is likely to be the cause?
    without the obvious "needs new rings" as i dont believe that this is the case at this point of time.

    i know that all of these options could fix the problem, but which is more likely to have better results?
    in a car i might try a heavier weight oil to reduce smoking or replace the valves/valve seats if it was smoking at cold or idle.
    ive never bought a car that hasnt ran in a few years, so i cant comment on that part of the question.
  2. Definately valve stem seals. Try some oil additive to thicken up oil. Or go to a higher oil grade. 15w/40 should do the trick.. If you want to be safe go 20w/40.. :grin: If its not blowing smoke when warm, then don't worry about a 50 grade, 40 is fine..
  3. What ^^ said.
    If it does it on start up, esp after sitting for a few hours or overnight, it's valves or the stem seals. Run it till warm, leave it o/night and see if it does it the next day.
  4. This might be a dum question but is it actually smoke? Is it just white water vapor as most bikes puff out on a cold start up?
  5. its smoke.
  6. Change the oil now, then take it for a long ride, run it up and down through the rev range, park it overnight and see if it does it in the morning. If it does, then I'm with the guys who say the valve guides are probably gorn. (Oh, and change the filter too, now).
  7. ive got a nice bottle of Penzoil 15W40 Mineral oil for cars sitting in the shed.
    could this be used or is mineral oil not suitable?
  8. i wouldnt use car oil in your bike. there's something about it which makes it unsuitable; friction modifiers or something along those lines.

    as for your bike, what colour 'smoke' is it? My guess is that it's only condensation. My bike does (well did) this for the first 5 minutes.

    But generally, if it's white smoke, it means your burning water.
    if it's black, it means your burning fuel, and if it's blue, it means your burning oil.