bob27s

My Feedback: (19)

You want the OS91FX turning around 12,500 - 13,000 rpm for best power

(remember, its an over-grown .60 size engine..... not a big-block .90)

Try a 12x8 or 12x9 ...... let that thing turn up.

also...
which ultra-thrust did you purchase? RPM version or the Torque version?

Bob