Hi guys,

I have a TT91 FS with about 2 gallons through, i've tried several props but none seem to be just "right" for the engine/plane (Seagull Extra 300), I think it's a heavy plane!

Zinger 11x10-> Not enough pull, not a lot of prop showing on the sides of the cowl
MAS 12x5 -> Too small, didn't even try it
MAS 13x5 -> Not enough speed, too small and too low pitch maybe?
APC 14x4W -> Engine revs nice and good thrust but no speed, this is a heavy plane and I need some speed
MAS 14x8 -> I feel it's just too much prop for this engine

I tried a Zinger 13x8 (wood) this morning, the high speed needle is very touchy and had a deadstick because of detonation, but if I use it richer the engine hesitates too much.

WIth this prop I tune it on the ground but when I take off, the RPMs drop when I go pass 3/4 throttle.

The timing is where it should and the valves have the right clearance

I noticed there is a small dent, VERY small, on the high speed needle (see attachment).

So...

a) Use a 2-Stroke on this airplane (I have a ST G61 that I used with this airplane with "good" results)
b) The high speed needle dent is the cause of my problems
c) That 4 stroke will never give me speed (speed is what I want)

Thanks for any advice
Joseph