RE: Saito 100
"There is no such thing as a "factory setting" on a model engine - this is the single most misunderstood issue in the history of aeromodelling! There are guidelines on where to start but every engine's low speed and high speed needle must be adjusted to where that particular engine runs best in that particular airframe with that particular fuel. "
So true and the cause of much frustation.
If the tank is too high in the fuse, could a smaller tank be used to lower the 'head' seen at the carby? Might be worth a try if it will get you into the air and get time on the engine. After break-in go with the original tank if needed.
My 65 is inverted and idles low and slow. Runs great on 10%.
I could never get my 45 to idle like the 65, but running 30% sure does help. The 45 is still low time so I'm hoping it will smooth out with more time on it.
Good luck, MikeB