Engine will not make power after carb install, post-overhaul

I'm with Skot on this. Because the previous carbs were modified, you really don't have a baseline for WOT static RPM with stock carbs and this prop setting. What RPM was the customer getting at Static WOT before you rebuilt the carbs?  What prop do you have and what is the current prop setting?

Agreed no base.

 In the end you need to test whether it is lean or rich at 4800 WOT, either a plug chop and read them or pull out the "choke" actually an enrichment device on these carbs., if revs go up it was too lean if they go down too rich. Then shift the needle accordingly and redo. I am sure there are good articles on how to tune these carbs on the Rotax...

Prop setting cannot he changed, it’s a fixed pitch sensenich. Before carb overhaul, aircraft made 5000 on the ground and full power in the air. Owner just ran it up and pulled the choke, and the rpm’s dropped. Not sure what that indicates as far as fuel mixture, but since rebuilding carbs, engine does not make power. 

Glenn, what do you mean by adjust the needle?

Conner

 You are a member of this Forum. Check out the free manuals, found at the top of the page "Support/Bulletins".

You will likly find the information on carburettor setting in Installation and Heavy Maintenance.

One other point not yet raised - are you sure the Tacho is reading correctly?