hmm...I haven't had to tune my 91FS, just did the usual break in which is 10 mins, set it up and it runs, two 91FS engines, accasionally you have to tweak the high end needle valve because of the weather changes. I really think this is brand preference. The guys at our field have had great luck with OS and swear by them. I believe it is a Ford vs. Chevy thing. Right now I have 2 OS 91 FS, 2 OS 120 AX, 1 OS 55AX and 1 OS 91 FX and they all run great, no problems at all.

Back to the Venus II and the star of this thread...I just noticed that my belly pan is broken, looks like everything else in the box is OK, but the belly pan showed up broken new in the box. I'll call tower and see what they say.