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

sorry all...forgot to add the reference from the installation manual.

Cheers

There are some SLSA fied pitch props on some aircraft. The first one comes to mind is a Tecnam Bravo. I took a wood fixed pitch off from the factory and installed a Sensenich. The old factory wood prop would only get 5200 WOT in level flight. I've seen a few others, but didn't swap them out. The customers didn't  want to spend the money. Static rpm at 4700 - 4800 can be normal.

Propeller is a sensenich, model W68T2ET70J, so a 68” dia. With a 70” pitch. Found the yokel who put this “special mixture” system ok had removed the fuel vent lines so we put new ones into the Rotax aluminum intake air box that’s on the aircraft, and rpm went from 5750 to 4860 at WOT. Adjustments to idle mixture screw have no effect, enrichening or leaning. At this 4860 RPM, fuel flow indicates 5.2 gallons per hour with boost pump OFF.  This seems like a high fuel flow value for low rpm, possible the prop is too coarsely pitched? 

Depending on whether it's  a two blade or three blade a static WOT rpm around 4700 +/- is fairy normal.

From your description of what you have tried it sounds like you have RAM air into your airbox.  The high pressure air is causing the rich mixture in that case.  Simply remove the tubes and put them under the retaining wires for the float bowl, like it was when new.

You have to change the airflow into the airbox otherwise the fuel air balance will never be correct.  Without EGT you have no way to determine this.  Perhaps consider some pictures of what it looks like currently for more advice?

Cheers