Hello!!!

I have my Saito for about month. It has about 4-5 liters thru it. I initially broken it in on fuel with 10% nitro and 19% oil synth/castor mixed. It was polish fuel, so i decided to buy something with more reputation and i went with Model Tchnics Formula Irvine 10% nitro/ 18% synth/castor. I remembered i liked this polish fuel more when i had Magnum 4-strokes but i hoped Saito will like more expensive fuel. It appeares it doesnt.
To make this engine work well from idle to full throttle i must have low speed needle very rich. If i set lsn for perfect idle i get very poor and lean middle range. Still on the ground whet i open the throttle about 1/3 and keep it reving it emits no smoke, sound becomes very soft, and when i rapidly give full throttle the engine doesnt spin up smooth. It chokes for a split second. It looks like much too lean. But when idling for about 15 seconds it smokes a lot when i open the throttle. Of course with such rich lsn setting the idle is not as smooth as it was with leaner setting. But i prefer this instead of destroying my engine by overheating it.
High speed is set with tahometer about 250 turns/min lover than max.
I write all this beacuse of the rich setting my Saito burns a lot of fuel and what worries me most my model is more dirty after 2 flights than it was before after all day flying.

What do you think- is this the fuel, or maybe i adjust something wrong? I'd be grateful if someone described how he adjusts lsn in his FA91.

Thanks

Pawel