what rpm is ok?
 

i have a 454 carb in my 272 baja, what rpm is ok to run ? i had it full throttle the other day in calm waters and it went to 6k rpm maxed, in ruff waters i was maxing about 5rpm only at full throttle, i was told to never go over 4500rpm is this correct? thax jim

oh its got a bravo 3 also

454 7.4L or 454 Mag? What prop you running? If you went to 6k your rev limiter is disabled. You shouldn't be able to rev it over 5200 regardless

Older carb motors wont have a rev limiter.

I wouldnt go over 5200 if its a mag,,,, less for the 300/330 hp

4800 to 5000 RPM

Must be a good solid motor if you got 6K rpm.

Make sure your Tach is set for 8 cylinders on the back of the gauge.

XT

its just the 7.4 454, as far as prop,im not sure, where would i find that info is it engraved on them? its a bravo 3 with dual props.

well can you pin the throttle on these boats? because 5k rpm i get without having the throttle all the way forward,theres still room to go more,thats why i ask..

Either your tach is not set on 8 cyl., or you need bigger pitch props.

I think your tach is off.

how do i figure my pitch so i know what im running?

My guess is a good prop to start with on your set up is a 23 pitch 3 blade. If you cannot get that prop to spin to around 5800 RPM then you have too much prop and need to back down to a 21 pitch. It is spins over 4800 RPM then you have an excess of power and will want to try a larger prop say a 25 pitch.

It is all trial and error based around matching the correct prop that puts your engine where it needs to be at WOT.

Dock, he's running a Bravo 3--dual props. He cant just throw on a 23 pitch 3 blade!! LOL!

If its the standard 7.4 litre 454 (not mag) then he should be running a max of 4800 RPM.

ok on my props it say 24P So im assuming they are 24 pitch props

that is correct..

IMO you need to take that bravo 3 off there and put a bravo1 on there with 1.5 ratio. If you've already got a 1.5 ratio upper just buy a lower to put on it. Then put a 22p Bravo prop on it or a 23p Mirage Plus. I've got 2 bravo1 lower DWP on both

On my carbed 272, the WOT range was 4200-4600 RPM. I could never get it to go over 4600.

Also, my 272 with a carbed 330hp 454 had a mirage 21 Pitch on it. Ran about 54/55mph @ WOT

you need to check the tach cause to spin two 24p props to 6000rpm is nuts or you are over trimming the drive, a b1 drive will be better for you.