Engine misfire and a puff of blue smoke...what could this be..?

Discussion in 'TR650' started by kiwiape, May 16, 2021.

  1. kiwiape Husqvarna
    AA Class

    Husqvarna Motorcycle:
    650 Terra
    Other Motorcycles:
    Aprilia DD750
    After not riding my TR for 18 months odd, I went for a quick 30km shake down ride and all was ok.

    The next day some 250km into our ride, accelerating through 80km I noticed one small miss fire, I looked in the rear view mirror and noticed a blue haze, at then same time my wingman (behind me) comes through the SENA saying WFT was that??? as he could see a cloud (reasonably large) of blue smoke.

    We stopped, looked and listened, check the oil level and all seem ok. We carried on heading straight for home just in case it was going to grenade itself. There was no problems at all for next 160km.

    Once home I checked the oil level and it seemed a little lower than before I left (but its always a guess with these bikes). I drained the oil and checked the drain plug, nothing to report and that's as far as I got.

    Tonight I will measure the volume of oil left and open the oil filter and inspect it to see if I can find anything.

    I am using is Motul 300V and it was only 3,000km odd old.

    Sump plug has only a very small amount of iron dust filings on it.

    Has anyone experienced this...?

    Attached Files:

  2. CarstenB Husqvarna
    AA Class

    Location:
    NL
    Husqvarna Motorcycle:
    none
    Other Motorcycles:
    F650GS Dakar
    maybe the engine burped some oil into the airbox which got sucked in and burned.
  3. PaulC F class

    Location:
    Bayside Brisbane, Australia
    Husqvarna Motorcycle:
    TR Terra
    Other Motorcycles:
    2 2018 YZ 450F, 2019 CRF1000AT
    Could the miss-fire have been pinging? With pinging I found resetting the plug gap would help. But never noticed any change in oil levels.

    Filings, I had about half that amount with every oil change, 6-8k intervals in 85k km.
  4. kiwiape Husqvarna
    AA Class

    Husqvarna Motorcycle:
    650 Terra
    Other Motorcycles:
    Aprilia DD750
    This is the most logical explanation (from the breather), so after I get the airbox open I will report back.
  5. kiwiape Husqvarna
    AA Class

    Husqvarna Motorcycle:
    650 Terra
    Other Motorcycles:
    Aprilia DD750
    This was a definite miss or single cough, short and sharp resulting in pretty good cloud of blue smoke, well visible in the mirror. My guess is the lump (for want of a better description) of oil blew the flame out.