253 convincer

[darrinw1]

bought 96 253 convincer last july runs wot 5200 rpm seems high what is the proper rpm range for this boat has a 454 with a mirage 21pitch prop. thanks darrin

 

[onthehammer]

What model 454 do you have?

 

[darrinw1]

7.4 liter mercruiser bravo 1 outdrive

 

[vinny p.]

7.4 or 454 Magnum MPI?

 

[darrinw1]

7.4

 

[happy]

ls series.. should run 5200.. b4 the rev limiter kicks in,, you should have a mef3 computer right/

 

[darrinw1]

you lost me on the mef3 computer

 

[happy]

send me the serial number of you engine.. i can look it up for you

 

[boatn70]

hes probably running the carb 7.4.
id have to check to see what mine was but i think it was around 4800-4900.
ive got some of the original manuals from my boat and merc, ill check on it......sometime. if its a stock motor setup, sometimes theres a tag on the motor, valve cover or thermostat housing that may give you those numbers.

mine was on top of the tsta housing.

b70

 

[miller time]

max rpm

I have a 95 253 with the 454ci 385hp efi and max rpm is 5200. I run a four blade 23p ss prop

 

[mboger]

a 7.4 shouldnt run that high and sure wouldnt last
i thinks its a mag or the rev limiter should be hitting

 

[Chris E]

i'm thinking 44-4800 rpm if the engine is a 7.4 carb 300hp

 

[happy]

52 is the # in this book.. that is the best i can offer.

 

[Superjet]

My 454 carb is either 4,600 or 4,800 max rpm.....don't remember....I was thinking 4,600.

 

[boatn70]

i think we're beating a dead horse here. if darrin doesnt speak up, we can all keep guessing but it wont help anyone!

 

[253 SED]

if its a stock 330 or 300...46-4800 rpms @WOT...Those small peanut port heads start floating the valves at 4000revs..just my 2 cents