2008 Merc 350 mag MPI won't go over 1700 rpms

[Dsampley1]

Hello All,

This is my first post I'm a new boat owner. My boat is currently having an issue where in throttle only I can go over 1700rpms however under load it won't go over 1700rpms and that's about 5mph on the water. Engine sounds normal. Major service recently completed at 100 hours. The boat is fairly new and just has 104 hours. I can't figure out the issue for the life of me. Wondering if anyone has come axross this before. I've seen the posts on 3,000+ rpm issues however those engineers are larger then mine.

any inside would be greatly appreciated.

 

[Dsampley1]

The boat is a Sea Ray 210 select 2008.

 

[alldodge]

Howdy

Tell us more about your boat. Has it ever run more then 1700 rpms under load?
What is the engine serial number?
What was done at the 100 hour service?

 

[Dsampley1]

Hi thanks for responding.

Yes when I purchased the boat we used it for the entire summer 2016. We would get at roughly 50mph as our top speed I don't recall the rpm at that speed but a significant difference at 5mph currently.

Where can I locate the engine SN?

During the 100 hour service we had the oil changed, all the filters changed (3 total based off the invoice). The drive was removed, inspected, gimble checked, a pump that goes in the drive replaced. Drive oil changed. Drive was recentered on the boat and engine retorqued down to the boat frame. The boats compression was also checked by the service center who advised it had great compression. The service center I go to is pretty honest and trusty worthy the owner doesn't try to nickel and dime you. The issue is they are booked solid for 30 days and that would cut my boating season in 1/2.

A few additional observations while under load is that inside the vessel was a very strong scent of gas and my brother in law behind me also smelled a strong odor of fuel. Engine didn't make any odd noises or viberations. The digital rpm gauge showed it would not go over 1700-1710 it was fairly consistent staying at that rpm.

Prior to this the boat had been winterized by the service center and summarized before the trip. I did fill the boat with fuel (put to the neck) prior to leaving for the camping trip.

 

[alldodge]

Smelling gas is not good.

Open the hatch and see if you have a leak. Changing filters (which include gas ones) can cause a leak if it is not installed correctly. Look in the bilge for water which may be gas. If it is gas don't turn anything ON, contact the marina and let them know

 

[Dsampley1]

While on the lake I inspected the engine compartment, bilge pumps off and we had not standing gas or seen any gas coming from any of the lines. I traced the line from the gas cap, to the tank (under the rear bench seat, back out to what looks like a housing in which the fuel/water separator resides in.

The fuel smell seems to only make its presence while at the 1700 rpm cap. My brother in law behind me said it was like raw fuel coming from the exhaust.

 

[alldodge]

OK. the serial number would be on top the motor or a plate above the starter on the engine block.

I would start with checking fuel pressure. Will need a pressure gauge that reads at least 100 psi and it would be connected to the fuel rail. The rail is on top the motor and will have a cap cover the shrader valve.