2013 F150 loss of RPM WOT

[Neversosure]

Hello all,

I have a 2013 F150 on my bay boat, I have 208 hours on it. The boat has always ran great, 5900rpm @ 41Mph, late last summer I started having a WOT issue. I am only able to get to 5300 rpm @ WOT......

This winter I changed the following:

F filters
VST filter
fuel filters
injectors
plugs

Still have the issue!!! Grrrr......

Boat idles smooth as glass, gets up on plane, but will not get above 5300 rpms,

Plugs had a little bit of soot on them (rich), I am banging my head over this.... loss of 600 rpms.....

Prop is fine, fuel is clean, not making oil,,,,,,

Taking all ideas....... HELP!


Matty

[99yam40]

is rail pressure in spec?
was is all plugs that looked rich?

[pstephens46]

And there is absolutely no way the boat weighs more than it did before. Just asking? Is it trailered or left in water?

[Neversosure]

is rail pressure in spec?
was is all plugs that looked rich?

I am checking the pressure tomorrow morning along with thermostat change. Only two were sooted up

[Neversosure]

And there is absolutely no way the boat weighs more than it did before. Just asking? Is it trailered or left in water?

No Sir...... boat weighs the same.... the boat is in the water..... fresh bottom paint. No extra gear added, no water.

[pstephens46]

You replaced or cleaned the four injectors?

[TownsendsFJR1300]

Which plugs were sooted up?

Prior to the issue, was ANY maintenance / work done to the engine?

[Neversosure]

I replaced the four injectors th is winter, I believe the bottom 2 plugs were sorted #3 & #4.

[Neversosure]

I am going to the boat today, I ran the boat last Sunday, I will pull the plugs and look at them again, the boat was running fine then started this issue last summer. I did all the work this winter before taking the boat back down again last week.

no there was no prior repair to the engine before this issue started.

[99yam40]

rail pressure would affect all of the plugs not just some,
but it is a good idea to make sure the pressure is in spec and stays in spec at all RPM.

what injectors did you get to replace the old?
did you send off the old for servicing to keep as spares?

might swap them back if they checked out good after cleaning.


how old is the fuel?

[pstephens46]

Would be an ideal time to find and use one the unicorns that Rodbolt talks about. The infamous test wheel.

wonder what hull is being discussed?

[Neversosure]

Changed the thermostat, the old stat didnt look too bad, I will take it home and toss it in some hot water.

checked fuel pressure at the rail, 40lbs +/- key on, Idle 40lbs +/-, 40lbs + at load wot.

Ran it same thing 5300rpms, I did play around and try to trim it up and did get it to 5500rpm but had dolphining going on and the rpms bounced to 5900rpms when motor trimmed up, but still not the top speed of 41 mph that I had.

pulled each plug wire 1 through 4 to see if I had a miss, no miss.

Last year the boat would run 5800-5900 rpms with little or no trim, still has power loss somewhere.

the hull is a 2015 Defiance 220ex.

gonna pull the prop have it checked as well, the prop has no vibrations or dings in it, but indont know what else could be the issue.

no added weight to the boat, no hidden water in the boat.......

stumped.

[99yam40]

fresh bottom paint means it sits in water a lot,
could the paint load up a motor some?
did it have bottom paint before?

does that boat have any wood in the hull?
stringers and transom.
no free water does not mean water has not soaked into wood inside the hull.

[Neversosure]

Fresh bottom paint, no more then a coat and the barrier
,

boat is 100% composite, no wood.

boat is 4 years old.

[99yam40]

maybe Townsends can comment of the fuel pressures.
I thought it was different than 40 all of the time.
he should know

I second the test wheel thought