I Have A 37 Single Step Stiletto, With 800hps, Speedmaster 5 With 1.34ratio, I Cant Get Over 92mph, I Was Running A 32x18 4-blade And Doing 58mph @ 2800rpm, And A Max Speed Of 92mph @ 5000rpm Due To The Rev Limiter, I Sent Out My Prop And Had Them Set To 34 Pitch And Now I Lost My Low End Speed Now At 3300rpm Im Doing 56mph And Still Same Top Speed Of 92mph, The Boat Did 105mph Before I Repowered It Over The Winter And Added 75hp Per Engine. Any Ideas????

Why do you have the rev limiter coming in at 5000 rpm.

What did your builder do to add "75HP"? If he added the HP at the expense of TQ there is your answer. Do you have new dyno sheets?

I turn my 600 cid motors to 5,800 quite often without issue. Turn up those revlimiters and have a blast...

Its already been said, rev-limiters need to go up 5500-5800. I dont know much about your set up, but the 37 we had ran 6's with 1000's, and we were running 1.5 gears and swingin 16X34 pitch 4 blades. 18 inches of dia, just seems like alot of prop, unless your drives are mounted very high. I went up to 16.5's to lessen the slip in the mid-range, 18 seems like alot.

raise the Rev. limiters and if that does not help, you did not add 75hp, you lost 100hp......what RPM were you turning when it ran 105mph????

Who re-pitched your props? I've seen a lot of people re-pitch props and have lots of problems. They all wound up having to buy new props.

pull the chip out and see what it runs! Seriously! The engines even if they are hyd. roller cams will turn 5800-6000 rpm

I would try some differnt props, almost certain whoever re-pitched them botched them up. Deffinately pull the chips out of the rev-limiters. Just keep an eye on it, but 5000 rmp seems a little bit too conservitive.

Does anyone know what the Mercury suggested RPM range was for the SC800 and SC900?