I don't have my notes with me, but Pat Johnston manifold, one direct from Pat--ditching the carb is real important for consistent runs. O.S. venturi, .281 I.D., PA NVA. YS 20/20 fuel. Always had some 30% helicopter fuel with me for those times when enough grunt just wasn't. Stock Sullivan 4-ounce tank. No muffler pressure. Two-blade, CF Berringer prop, albeit a Chris Cox/Alan Resinger piece which was on loan from PW. I used an Eather 12-5 three-blade as a back-up, but the Berringer piece was generally a little better. I fiddled some with ground settings, ended up using 8400 to 8500. I didn't care for runs which began with a ground setting over 9000. YS four-stroke plug (made by O.S. for YS, just different markings on the body--functionally identical plugs). All flight settings made with a tach. And patience, especially the first run of the day--lots of metal to get heated. I would find a peak, it would generally be a false peak. I would then find the real peak and simply back it off 50 to 100 revs. I had no luck with simply listening to the engine, but Randy Powell sets his by ear, so I know it can be done. My first Saito 56 plugged into my first Impact, which was oringinally built around an ST 56. Second Impact built for a Saito 72, retro-fitted to a second Saito 56.
As I have said before, a per-plans Impact with a Saito 56 is a good combination, one I have suggested to several as being appropriate for their specific needs.
The only real issue here is whether or not the above is the best for my specific application, going into 2007. And clearly it is not.
One of The Tests: When you get to the fourth corner of an inside square, does flying the model still feel like slow motion, assuming it did in other parts of the pattern?
Another Test: Same deal, third corner of the triangle.
And another: First loop of the four-leaf clover; are you sure you couldn't use just a wee bit more grunt? If so, that one-speed motor ain't never gonna be able to deliver.
And that is one of the things I personally don't like about the Saito 56: Too much of what I at one time thought might be a Good Thing, that one-speed charateristic.
Dan