912 ULS no more than ~4800 RPM

I've had debris in the float chamber cause similar symptoms to those that you describe. I would take a look and also check the fuel level in the float bowls. It is quick and easy to do.

My only other thought is do you have any restrictions in the float chamber vent tubes? Are they routed correctly and not subject to anything other than the ambient pressure inside the cowling?

If you normally get about 5100 rpm on takeoff the engine is on making about 75% of its rated horsepower. Sounds like the propeller is over pitched making your engine work harder than necessary.

Hi Kevin, nothing has changed since my previous flight and it was ok.

Ah! but something has changed, otherwise you would not be contact us.

Ah! but something has changed, otherwise you would not be contact us.