New Formula Owner
 

I just bought an 01' 27 fastech.It's got a 375 hp 496.Can't get on plane very well,it only tachs at 3500 rpm's and once it's up it will only rev to 4500 rpms.Is this normal?Local prop shop said to leave the 22 pitch prop.Bennett tabs don't seem to help any.Any ideas?

contact BBlades or a HP shop that knows these boats. The prop section will help you

sounds bad...............

I have an 01 271 also, with a 496HO/425hp, 24P Bravo w/ bennet tabs. WOT is 4400 at 59mph (non GPS), coming on plane could be better and I can slow it down to 25mph using full tabs. Most of these observations come from having 2-3 adults on board w/ 1/2-3/4 fuel. After looking at the prices of bigger/better tabs, I decided that if I do anything at all, it will be using 2 props, one for top end and one for slow speed, towing the kids around on a tube etc. If you find that magic tweak, let me know. :D

That prop is too small you should be running a 26 if it is a bravo 1 and that boat should not need any tab to get on plane.
They come from the factory with the 26 and all the ones here I see have no problem . Once on plane are you getting it trimmed to acheive RPM? Small prop will make it hard to plane.

Not just me
 

slivings, sounds like our boats are the same and I glad it's just not me!When you are coming on plane do you know your max rpms?My boat full throttle coming out the hole is only 3500,seems a bit low.

Donzilla, if I put a 26 on, won't the rpms drop more?It's only hitting 3500 out of the hole and yes it is a bravo 1.Once on plane and trimmed it's at 4500.I'm hoping it's not an engine problem!

I normally don't come out of the hole WOT, and I haven't really paid attention to the RPM's then, But considering I'm not WOT, it seems reasonable that 3500 would be about normal.

Wot out of the hole will cause drive failure eventually.Plus that motor Hits the rev limiter at 4850. Something not right you should be able to turn a 26 b1.Unless you are way heavy with gear fuel and people?

Donzilla is right, hard-hitting holeshots = broken drive sooner or later. in 2002 Mercury made some changes to the Bravo I which strengthened some weak points, but WOT before plane is still something to be avoided.

Take a look at this for info on Bravo failures:
http://www.go-fast.com/bravo_drive_failures.htm

Here is a matrix of improvements in 2002 Bravo I drives:
http://www.go-fast.com/mercruiser_bravo_sterndrives.htm

Even if you are fire-walling the throttle out of the hole (which I agree with the others is not good) you won't turn up full RPMs. The props/engines are just too loaded at that point. You won't see full RPMs until the boat airs out on plane.

As for the prop size, 22 is way small. As stated above, 26p was factory stock. 271s have always been notorious for bad planing. Friends have an 02, 502, 26p. It blows the prop out bad on take-off. You have to nurse it up on plane. Very slow to plane but not because of too much prop. It just looses bite. But, once planed off it comes up to 5000 easily.

If you are looking for serious more power for your 271 with 496 Mag just change ECM and camshaft and make it 425 HP or add a Raylar Kit and gain up to 225 HP without supercharging

He needs a prop first.

Sounds like my prop guy doesn't know what he's talking about!He said don't change it.I will try a 26, it can't hurt.Thanks for the feed back.