very heavy smoking on 200 cc engine

[rg500g]

The saga continues.  The bike shop is trying to resurrect a 200, and we got it to the point that it starts.  Now we see horrendous smoke and oil spray coming from pipes.  The mech just took off a pipe and oil dripped out.  Checked trans oil level and it's lost a lot.  Obvious conclusion - trans oil getting sucked into combustion chamber.  Looked at shop manual and parts book and can't see how that can happen.  We're now considering leakdown.  If anyone has guidance on diagnosing possibility of trans oil getting into cylinders please respond.  We are going to pull oil feed pipes from pump, pull oil feed to pump, and run premix.  We're only starting the bike and idling it for 30-60 secs with minor throttle blipping, so I don't expect pump to be damaged running at fairly low revs w/o an oil supply.  We'll block oil pipes to spigots downstream of carb to eliminate air leak.  Mech just informs me that the left pipe is pretty dry, so the right one is the major culprit.  It sprayed oil on the floor.  Oh boy.  I really don't want to split the cases.  This is a new rebuild with fresh crank seals, etc.

[bsracer]

I would guess that it's either the RH seal or the oring in the rotary cover. I have also had trans oil make it past the collar and the crank gear. You should do a pressure test. That will show you where the problem is.

paul

[OldSwartout]

If they check the right oil seal & rotary valve cover o-ring, there is supposed to be an o-ring behind the sleeve that goes under the oil seal, but I've seen them run OK without it.  The bottom end may have gone back together with the locating pin for the center crankshaft bearing not engaged in the notch in the bearing.  That will keep the crankcases from coming together and let it suck lots of transmission oil. That is not likely, so check everything else on the right side thoroughly first.