Chicago290

Hi guys, recently bought a new boat...well it ten years old. Its a powerquest 290 with 23p 3 blade mirages. (i believe this is factory fit) It also has 330 hp 7.4Ls. It turns just shy of 5000 RPM at WOT. Doesn't this seem a wee bit high for a factory set up? It just does not seem like a safe level..input? thanks

dean51267

I turned my 93 model 330hp 454's 5,000 all day with no problem, I think factory specs are that power loss starts at like 4800 rpm though....

GOODT

the above is correct, the revlimiter will kick in at 5200 if im correct you should be between 4400-4800 rpms go up one pitch size

for every inch in pitch you go up you will go down in rpms aprox 200 rpm

Whiteknuckle

Thats perfect, leave it alone and don't worry about it. Who ever had the boat before you has it propped perfect.

Chicago290

Thanks for the input guys. Think i'll just leave her be.

BajaRunner

thats high isnt it? I thought you didnt want to rev over 4600 on the 7.4's?

Pat McPherson

I found that my 1989 330HP/7.4Carb made peek power at about 4900rpm. At least propping my 24' Pantera there was the fastest.

I had a 1999 310HP/7.4MPI in my 24' Super and that pushed the boat fastest propped at 4500rpm.

I believe that the Gen VI roller cam 7.4L engines peak sooner than the flat tappet cam Gen IV & Gen V engines.

The engine should live at 5K, but I'm surprised that it does not have a rev limit before.