Too high of 7.4 RPM??
 

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

Re: Too high of 7.4 RPM??
 

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....

Re: Too high of 7.4 RPM??
 

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

Re: Too high of 7.4 RPM??
 

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

Re: Too high of 7.4 RPM??
 

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

Re: Too high of 7.4 RPM??
 

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

Re: Too high of 7.4 RPM??
 

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.