Again It's just a sample space of one but it has about a hundred flights with out the choke and no problems even when the tank is close to empty. It's just a steady strong engine and the needles aren't very sensitive.

The fact remains as discussed in a thread concerning Saito's, this extra extension of the carb venturi will help keep more of the "reversion bounce" fuel in the carb and not all over the engine compartment. This will lead to a more consistant mixture and better overall fuel economy.

Enjoy,

Jim

I'll just keep the choke assembly on! Hehehe ... would a 15x6 (I know a 14x6 will be fine) be ok as its on a WACO 60 for scale flying, just want to do big loops and stall turns.

The TT 91 likes to turn up some rpm. A 15-4 might be OK?

I tried a 15x4W on a short flight so could not really tell, its just that my aluminium spinner will not handle a W blade and I was tempted to go with a 15x6 on lower revs. I shall experiment ...

I've run a 15-6 on a Y-S 91 but it is supercharged. Don't know about the Thunder Tiger?

Enjoy,

Jim

The TT .91 doesn't like the 15-6. It will turn only about 8,000 or so. If you do run a big prop, lower the nitro and use a colder plug, such as the K&B 4C. It will detonate and run hot if you do not do this.