912UL Miss Below 4,000rpm

Thanks for all the comments and suggestions. It appears that the recent carb overhauls noted in the logbook were incomplete.

The o-rings on both the idle jet and idle adjustment screw were flat, hard and brittle. Most likely the idle jet was leaking by, creating an extremely rich situation.

We'll know for sure, once I get them installed and balanced. But if that wasn't it I don't know what else it could be.

Stay tuned!

Any luck?  

Yes,

Believe it or not it was the gear set that was the issue. I replaced the gears and the issue went away.

Glenn

So the gears in the gearbox caused the engine to miss? What would cause that?

Ross