Finally seemed to have solved the problem. Looking at the low speed needle valve, when leaned properly it actually was sticking into the spray bar a short way. After filing about 1/2 mm off of the low speed needle valve in the shape of a point at about a 45 degree angle the engine is now a *****cat, transitions and idles perfectly. Since I had nothing else to use I did this by inserting the needle valve into a hand drill and spun it on 220 wet/dry sandpaper with a little oil. All on the same 13-8 prop, which by the way is one of the suggested props listed in the Saito manual accompanying the engine. Since I had already replaced this engine in my 4*60 with an OS91 I will be using it in a Sig Hog Bipe under construction in, hopefully, the near future.