PLEASE HELP HAVE A 1/4 SCALE HANGER 9 J3 CUB WITH A NEW OS 120S- E ENGINE INSTALLED AEROPLANE HAS 3 FLIGHTS
WITH 5 TANKS OF FUEL USED ENGINE RUNS FINE ON THE GROUND RUNS OK WITH NO CHANGE IN RPM WHEN HELD VERTICAL
ENGINE STARTS TO DIE AFTER TAKE OFF THEN PICKS UP AGAIN WILL FLY OK FOR A FEW MINUTES THEN STARTS TO DIE AGAIN
ENGINE IS INSTALLED INVERTED HAS A MPI GLOW DRIVER CONNECTED 16X6 CLASSIC PROP SIG 10% NITRO 1/2 CASTOR 1/2
SYN ,AND IS REFUELLED WITH A MPI REFUELLING VALVE THE AIR EXIT IS DOUBLE THE AIR INTAKE SIZE .THE IDLE MIXTURE HAS
BEEN LEANED OUT SO A SMALL AMOUNT OF WHITE SMOKE COMES OUT OF THE EXHAUST WHEN THE THROTTLE IS ADVANCED
ENGINE ALSO HAS A PRESSURE FUEL SYSTEM

HOPE SOMEONE CAN HELP
REGARDS KIWI TWO.

Check your idle mixture by clamping off the fuel line as close as possible to the carb. Rpm should rise slightly before the engine starts to die. If it quits abruptly, the mixture is too lean. If it runs a long time before the rpm begins to increase, the mixture is too rich. Give that a try and see if there is any difference in performance.

THANKS, WILL GIVE IT A TRY
REGARDS KIWI TWO.