Rotax engine issue

Carlos Plaza · Joined: 19 Jun 2012 Posts: 8

I just rebuilt my rotax. Put new seals and bearings in the case piston,rod and cylinder head. I didn't mess with the reeds or carb. They were working fine before. When I try to start it I have to use the choke or it won't start at all. And about 15 to 30 seconds after it fires it revs to 8000 on its own. I've checked the throttle to make sure it wasn't that. I know that the piston has to go in a certain direction. I've already tired it both ways but still does the same thing. Also it seems to be pushing some oil in the line that goes from the crankcase to the fuel pump. It never did that before. Any help would be great. Thanks.

Greg Wright · Posted: Mon Feb 11, 2013 11:39 am Post subject:

Air leak, could be crank seals or ????
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Joey Guyon · Posted: Mon Feb 11, 2013 6:11 pm Post subject:

You might have installed the seals on the wrong side. The balance gear side seal is larger I.d. if it is on the opposite side there will be huge clearance. You can spray the clutch seal with wd 40 and it will bubble if incorrect. The engine will also be harder to turn by hand as the clutch seal will be super tight on the balance side.

Or your slide is in backwards and isnt closing.