I have a 1994 35 fountain Lightning that has the 502 415hp engines with Bravo 1 drives. I was told the Bravos hve the 1:32 gear set as the previous owner ran some high HP engines before selling with these stock 502s. I am running Mirage 23p props and the best I can do is get 64MPH at 4300 rpm. I have a hard time believing I should step down to 21p props even if I have the 1:32 gear set. Is there something else I should be looking into or do I run 19 to 21 pitch props?

Look on the decal on the side of your drives and it will have the gear ratio stamped into the decal along the bottom. At least then you will know the ratio for sure. As for your performance problem I would think you would be seeing 46-4800 rpm.

I turn my 502s to 5250 and my rev limiter is set at 5400. I would keep the RPMs at WOT between 4800-5200. I think merc recomends 4800-5000 with the 502s in stock form. Based upon your numbers I would try a 20P Bravo 1 4 blade or a Hydromotove 20P 4 blade.

4300 to low . i have 136gears in my drive .yes you got to go lower in pitch. it will work out good . prop your boat to max rpm . i have a 24baja 718hp i run a24bravo 1 prop running over 80mph and i ran a 23mirage prop too.http://www.youtube.com/watch?v=jmnD9..._order&list=UL here i am racing a supercharge wave runner. you put the rigth prop you will be surprize how it picks up. your prop is the most importane thing it put you in the power band so like i said prop your boat at the max rpm and you will be happy i for got i put a 150gears and went to a 28bravo1 blew up my drive. so i went back to 136 drive like them better

Not if the owner relaxed the stock gears, which it sounds like he did.

The other boats I had in the past were Bravo 1 and they had the 150 gear and I turned 25p props on a 30' velocity. I'll prop down till I get the rpm up. I am surprised the gear ratio makes that much difference. Thanks for info

25 pitch props with 1.5 gears at 5000 rpm has the same theoretical top speed as 21 pitch props with 1.32 gears at 5240 rpm. With 23 props rpm would be 4780. Just a fyi.

For reference, I spin 24" Bravos to 5100rpms with 1.36 drives on my 32 AT with 502mpi's. I see 72-74mph.

Thanks for the info,,,4300 rpm is the best I can do. Based on the info you have I am almost 500 rpm below where I should be. I intend to check compression soon and see if that is part of the problem.

Thanks for the feedback. I should be getting a lot more than 4300 rpm with mine. Glad to see some first hand data on the 1:36 drives. I am convinced mine should be doing better than it is.