thunder tiger .61

A very nice engine, I use a Master Airscrew 12 X 6 (as it looks more realistic when stationary than an APC) on large RCM Trainer 60 and for a fast sports model, an APC 11 X 7 which could be said to be a little quieter.

What prop size would be best. I like APC best. It will be going on a own design, kinda pattern, kinda sport, kinda heavy. I'm thinking no more pitch than 6, as I'm a bit rusty, skills wise.

I like the 12x6, but most of the others were letting the engine spin up without doing much. That shortens the life a bit.

If an 11x7 is causing you to stretch out your landings, I suspect that your idle speed is a bit high. Maybe carb settings should be checked. If you still can't idle low enough with the carb readjusted, it might be time to experiment some with glow plugs. An 11x7 prop should not be causing a problem. I have flown 11x8 props without a problem.

Ed Cregger

IMHO, the Pro .61 is pretty porky for it's displacement. Also, mine tends to have rich midrange that can't quite be tuned out. Not exactly a powerhouse either. Clarance Lee suggested an idle bar plug for this engine to help with the midrange burbles. What it does do is start easily and never deadsticks.

Rein

An OS type 'F' plug gets rid of the fat midrange just fine. My TT61 has never had the power that my old OS 61 still has after 30+ gallons of fuel. And yes, chose your favorite 12X6 prop.

remove my-wife to reply :-)

Funny it weigh's almost exactly the same as the OS FX .61. People say this after just reading manufactures specs, well the TT spec is weight with included muffler, OS is weight without muffler. That is about a three of four ounce differance.