Well I fired up the OS 15 FP, smallest engine I've run and it doesn't seem to have much. The spad I'm building is from the Web site Spad to the bone, called Hell on Rails. Finished it tonight and seems heavy for that little engine. Ran an 8X4 MAS and peaked it 13400. Richened it up a bit to run at 13100. Is this about normal for a OS 15???????????