I HAVE A COMPUTER MODULE AND PROP NECESSARY TO TURN YOUR OPTIMAX 75-90 TO 115
NEVER GOT A CHANCE TO USE IT THE COMPUTER HAS 63 HOURS ON IT IT IS OFF A 2008 OPTIMAX 115
JUST 3 PLUGS 3 BOLTS EASY INSTALL . INCLUDED IS THE 21 PITCH STAINLESS PROP, GAIN OVER 13-15 MPH DEPENDING ON YOUR SET UP