Grease on crank seals and output shaft seal ?

Discussion in '2 smokers' started by nick2ny, Apr 5, 2020.

  1. nick2ny

    nick2ny Been here awhile

    Mar 5, 2009
    Howdy all- I am rebuilding a Rotax 122 for my old aprilia tuono 125 and would like to know if I need to put anything more than a bit of two-stroke oil on the sealing lips when assembling.

    I only put oil on the magneto-side crank seal and the output shaft seal (forgot grease), but am about to install the clutch-side crank seal and am wondering if it is worth greasing it, or if the gear oil will oil it (on this bike, both crank case sealing lips face left).

    help !


    Screenshot 2020-04-05 at 16.19.25.png
  2. bark sampler

    bark sampler Been here awhile

    Mar 30, 2008
    Middle of Michigan
    Oil is good, grease is better. I’ve been using SuperLube for this purpose as it’s a little more oily and a synthetic without a lot of fillers. Some people use white lithium, others moly assembly lube, all seem to work. If you put some oil on the seal lips before assembly, it will be fine.

    When I knew less I rebuilt a Rotax 2-stroke (Air cooled Can-Am) without lubing the seals and they held up despite likely being dry on start up. I’ve heard of examples where the seal life was very short from the heat of no lube on start. I don’t know if the Rotax seals were better or I was just plain lucky!