Rick G

My Flat deck is powered by 605 ci in NA motors that we estimate to be approx. 700 to 725 hp. I am now in the prop and drive height tuning phase of this curse we call HI performance boating enjoyment. My flat deck has a notch and I am running SSM V drives with 3 inches of spacer currently set at 3 inches below the hull bottom and 17 by 25 pitch 4 blades ( don't know the rake ) . I have no issue seeing low 70's at 49oo rpm . I know I have to start removing some spacer as I believe the drives are too low . But am I running a prop diameter that is too large or is the pitch too small/ large ? we are upgrading the stock merc distributors to the MSD pro billet marine units this week as the old distributors are a tuning draw back .
any insight would be helpful .
Thanks RG.

MILD THUNDER

iTrader: (3)

I would try to get some hard numbers Rick, and jot them down before removing spacers. Like cruise speed/rpm, top speed/rpm, what trim it takes to get best speed, and so on. Then remove spacers, and do it again.

These old boats with speedmasters, are really their own breed, and each boat is different as far as what they like, setup, etc. Glad to see you get it on the water and doing some tuning