98 270SE max rpm

[MHorn0817]

What is everyone seeing for Max RPM out of a 98 270 SE with 7.4 liter MPI and Bravo 3 drive. Ours is 3800rpm at 33mph (gps).

 

[techmitch]

What is everyone seeing for Max RPM out of a 98 270 SE with 7.4 liter MPI and Bravo 3 drive. Ours is 3800rpm at 33mph (gps).

Not sure what it should be without looking it up but I do know that is way low.

 

[MHorn0817]

That's what I was thinking too. From what I've seen searching the web, it's anywhere from 4200-4500. The motor is fresh rebuild as well.

 

[Jeff Delbuono]

 

[MHorn0817]

Thank you but my motor nor my drive is on the list.

 

[scoflaw]

No matter what you have it wont be below those numbers posted

 

[MHorn0817]

Correct. I just stumbled upon a sea ray brochure that says 4600rpms.

I'll have to see what size props are on my boat, I just assumed factory. If the factory props are installed should I drop down a pitch or should I look for any type of other problem that may cause low rpms?

 

[blaster]

EFI or MPI? 4200-4600 or 4400-4800 it’s still low. Maybe you can tell us your story. Are you the original owner? Is this a new problem? When was the last tune up? (plugs, wires, cap, rotor, clean throttle body, backfire flame arrester, fuel filter). These maintenance Items make a world of difference in performance.

 

[MHorn0817]

Mpi.

I am the new owner, there were 3 owners before me. Motor was rebuilt 2 years ago and has about 15 hours on it. I'm not sure if it's been like that since rebuild or not. Last owner said he never went WOT.

So I'm assuming everything is 2 years old when motor was rebuilt.

 

[Jeff Delbuono]

I had the same issue when i got mine 4 years ago. After spending a month or soo pulling out my hair, swapping all little senors and a re prop. It ended up being a timing issue. 10 minutes with a merc master tech and a timing light it was fixed. Boat ran great on land, at dock but would not ever go over 3200 rpm on either motor

 

[MHorn0817]

Oh wow, now that's something I never really thought of. When I think fuel injection, I don't think of manually adjusting the timing. I figure the computer handles all of that.

 

[Jeff Delbuono]

Also, double check your wires. Make sure they are in the right order on the distributor cap. Another common mistake

 

[MHorn0817]

I'm going to start with replacing plugs, wires, cap, rotor. The props are original 24p props. I did find its supposed to be 4200-4600 rpms. I also found in the records that the boat has been 42mph at 4200rpms.

I did find a procedure to check the timing as well. Just need to jump the connector by the ECM, which I would have to find first.