Balancer shaft seal replacement

And still not getting the riding I was hoping to cause of colds and flus seeming to replace each other.

But this winter while looking over the bike and replacing a cylinder base gasket after starting it up it was not running good at all so carbs were next.

Then relocated the crank case ventilation into a catch bottle:

Catch bottle

And caped off the air box with a pen cap and some duct tape:

Caped air box

And after just a little riding there was some oil in the bottle:

Some oil

So stripped the bike to get access to the ignition cover:

All ready to lay down

Laid bike on its side to not have to drain the oil:

Ready to take cover off

A piece of paper to organize the bolts, notice there are washers on 3 of the bolts:

Bolts organized, notice washers

Pried out the old seal:

Prying out old seal

New compared to old, part number: 0760122050

New vs old seal

Hammer and socket to drive the new into place:

Driving the new seal in

Made sure it was nice and oiled:

New seal in place and oiled

New gasket in place part number: 60030040100 This gasket can usually be reused since its a metal gasket. Used a coulpe of lengths of threaded rod to help guide the cover into place since the magnets on the flywheel will try to pull it here and there, make sure to keep track of the 2 dowels:

Ready to get cover in place

Had some trouble getting the sprockets from the starter to line up and get it into place, got some help from my dad holding it while it while I squeezed a finger in there to spin the sprockets until it got into place, also had to undo the regulator and clutch slave for it to clear them when using the guide rods, gear lever I just held down while cover passed:

In place

Also found that I was missing a bolt holding the oil pipes and another of the bolts were quite far out lucky to catch this before a major break down happened, even had a spare bolt with the correct dimensions:

Found a replacement bolt

Drained the oil from the catch bottle, will see if it separates into oil and water, but have no signs that Im loosing coolant:

Oil out of catch bottle

Seemed to be alot of oil in the clutch part after having it on its side:

Hmm all oil in the clutch?

Fired right up after putting it back together.

And after the 20km ride home it looks promising that this was the cause of the oil in the catch bottle but want more riding done before putting the hose back into the air box.

An update, this is what the content of the catch bottle looked like after separation:

It separated

And as you can see there is quite a bit of oil on top and some greyish water gunk on the bottom.

Was not able to get similar sample from the catch bottle after the seal was changed since the bottle got a leak and I needed to button the bike up to head for russia.

Might look at bringing the hose back out next summer to get a comparison but from what I could see there was less oil in what was coming out of the ventilation.

8 comments to Balancer shaft seal replacement

  • Heya Dirtyadv

    Thanks for your breather seal article, we are Sucre, Bolivia with a Voltage Reg and Stator problem (which is nearly sorted) and your article helped me through the task of talking the LHS cover and getting it sorted.

    Much appreciate the time you took to do the writeup with the pics.

    Cheers man


  • Noah Carstens

    Even five years later your article will help me out. Thanks for that!
    From Amsterdam

  • Anthony

    Excellent post,common problem then and a reasonably easy fix.
    2009 990 SM

  • Hugo Carvalho

    Looks like I have the same problem. I was just wondering how the oil was going to the air box. Your article is excellent. Thank you very much. My mechanics didn’t know what the problem could be.
    I will try to do this myself.
    From Portugal.

    • Johan

      Its a quite easy fix. Hardest part is getting cover back on since the magnets in the flywheel pulls quite hard.

      Have had it off in the past for other reasons but really liked having the lenghts of threaded rod as guides even if it required unbolting a few more things.

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