Replaced the OS Max 46LA with another OS Max 46LA. Purchased two together last year.
Did not change the uniflow tank or the Crap Trap. Did back flush and clean out the fuel tank. Did back flush the Crap Trap. Used the SIG fuel purchased in Apr 2015.
Started the engine with in 3 flips. It flew 5.1 second lap time and engine did not flutter.
On the Problem engine, I removed the needle valve assembly. Removed the needle. Was able to look thru the needle valve throat. It was not clogged (no obstruction).
Put the disassembled needle valve assembly in a container of lacquer thinner and agitated. A black material appeared in the solution. It seemed that there was an obstruction in the needle valve body opening to the ventura.
Reasonable sure that that was the engine run issue.
Reassembled the engine and put some After Run oil in the engine.
Thank each of you for the timely info in running this issue down.
T Michael Jennings