tuning question or problem
 

I have an OS .46 LA. I am having trouble with setting a low idle in the plane. I have the engine mounted at a 90. the engine runs good and revs out but once it returns to idle it dies. the only way to keep it running is keeping it at 28-3000 rpm anything under it dies. I pulled the engine from the plane and resealed everything and bolted it to the bench, it run fine and would keep a stable idle at 18-2000 RPM but once back in the plane the problem returns. I already replaced the fuel lines to the tank and inside it, just to rule that out. what else can it be? at that idle the plane creeps away.

RE: tuning question or problem
 

Bring it to the lowest idle that it will maintain and pinch the fuel line.

The engine should run for a few seconds, during which time it should increase in RPM. Then it will die.

If it dies right away, the low end is too lean. If it runs for more than a few seconds, it is too rich.

The LA series has an air-bleed adjustment on the low end, so if it is lean, close the adjustment screw. If it is rich, open the adjustment screw. This regulates the air coming in that tiny hole in front of the venturi - also check that the hole is not clogged.