Rotax 912 wont turn over with the starter

[dalords]

Pretty much at a loss. Here is what happen. Was spinning the motor over with all plugs removed and prop off checking for a voltage problem I had with the stator. engine worked great. came out the next day to test again and engine would not turn over. Battery charged. Tried to turn it over by hand using the bolt on the flywheel. Got it to move but extremely had to turn. Tied rotating from the prop flange and it was almost impossible to turn over. Removed engine for stator problem. reinstalled starter that I had removed previously and tried to turn it over again with the flywheel and stator removed, again plugs out and no go. it is extremely had to turn over with the flywheel bolt. NOT SURE what it could be. Sprag clutch? or Prop gearbox slipper clutch? Gearbox crankshaft bearing? Anyone else have any similar problem

[Av8r3400]

I am afraid you have hydrylocked your engine. :eek:

The 912 uses crank case pressure to push oil back to the tank. If you turn the engine with the spark plugs out, it will not generate crank case pressure to return the oil and you fill the case with oil.

At this point I would highly suggest you contact a Rotax service facility (LEAF is a sponsor of this site, Brett at Extension 154 (http://leadingedge-airfoils.com/techhelp.htm) is their guy for phone help) to see how to drain the case properly and hope and pray you didn't damage the bottom crank and rods.


Lesson: never, never turn you 912 more than a couple revolutions without spark plugs in it.

[Av8r3400]

There are procedures to check the charging system with a multimeter that don't require the engine to be turning.

Brett can help you with this too. He is extremely knowledgeable on Rotax engines.