912 UL First ‘start up’ issues

Lots of issues….

You need to verify spark.   

Did you purge air from oil lines per Rotax instruction prior to first engine run?

Yes, floats should stop fuel flow when float bowl is full.  Check to see if bowl gasket is seated correctly.  Also, check float weight.  Each pair of floats (2 floats) should be less than 7 grams total weight.

VDO sensor is cheap from Amazon. Replace spark plugs.Try starting with throttle closed,choke full and boost pump off.

I would test out your oil pressure sensor and gauge combination. Just remove the sensor and connect and airline (below the max sensor pressure) or a foot pump and just see that you get a sensible reading. If you don't you need to fault-find the problem. If you do get a reading then you aren't building oil pressure and you need to resolve that. Unless you have purged the oil system as per the Rotax manual you are unlikely to get the oil to the pump.

If your fuel pressure is not rediculously high then the needle valve should certainly be able to shut off the fuel to the float chamber. If it does not then you need to fault-find the cause.

Thank you for the reply!  Air/Gauge test sounds perfect.

Upon removing the carb bowls, I believe it is a good time to go through both and clean them up.

If I don’t have any luck verifying spark…on #3, (have new plugs on hand) what’s the recommendation for troubleshooting?  

thanks again !!

https://www.rotax-owner.com/en/videos-topmenu/free-videos/695-Rotax-lockwood-ignition-troubleshooting for your no spark issue.