VP 4.3 MPI sluggish on holeshot

[Scott06]

A neighbor asked if I would take a look at their boat - 21 ft Larson 2011 ish vintage , VP 4.3 fuel injected (GXI I think).

The neighbor is a excellent slalom skiier she commented that her and her skiing buddy both thought the boat was sluggish on holeshot pulling up a skiier.

Boat is maintained by a competent marina and gets annual service during winterization and has about 400-500 hrs on it. She commented that had just had a tune up done including spark plugs. Did not describe a misfire or poor idle.

While I have a lot of boat and automotive mechanical experience I don't have any MPI experience.

Was hoping to get a low hanging fruit checklist from you guys.

Was wondering if they put the wrong plugs in as I though injected motors were sensitive to not using platinum plugs?

Does anyone know what spark plugs and gaps should be in there? Any idea what ignition timing should be at idle and all in?
Is there any notice of stored codes like beep when you start as I don't have a rinda etc that can log on, nor do I necessarily want to get that deep into it.

Any suggestions as to what to look for beyond basic stuff like fuel filter contents etc

Thanks

 

[alldodge]

Fuel pressure should be 43 psi at 1800 RPM
Plugs AC 41-932 gap 0.060
Timing is HVS distributor and is set by position and not but a light

 

[dubs283]

Upgrayed to a proper slalom boat.

Nautique mid 80s is good, pcm, motor oil in the gearbox

Prostar? Forget about it. Indmar performance is hard to beat

Skiers choice, they're okay

Bottom of the list is centurion, ugh.....

Genmar is decent ski quality, flat enough wake. 4.3 mpi volvo 2001 vintage should use flat cap or hei. Let's see some pictures, no gto

 

[ejnichol]

Is this sluggishness a new thing or was it preforming satisfactory in past but now not so?

If its always been this way try a lower pitch prop.

 

[dubs283]

If its always been this way try a lower pitch prop.

If it's always been this way why would anyone post?

Larson, volvo, sx-m, prop, flat wake, speed, hole shot, genmar

 

[ejnichol]

If it's always been this way why would anyone post?

Larson, volvo, sx-m, prop, flat wake, speed, hole shot, genmar

Because there not happy with holeshot/pullout. They need to try a different prop then if engine is performing as designed.

 

[Scott Danforth]

Check fuel pressure at WOT. Could have the VP paint issue in the fuel cooler

 

[Scott06]

Fuel pressure should be 43 psi at 1800 RPM
Plugs AC 41-932 gap 0.060
Timing is HVS distributor and is set by position and not but a light

Thanks apprecaite the comments. Wondering if the mechanic put wrong plugs in …

 

[alldodge]

I would suspect timing before plugs. Even with wrong plugs it should do ok

 

[Scott06]

I would suspect timing before plugs. Even with wrong plugs it should do ok

Well it’s always the simple stuff … flame arrestor completely clogged with fuzz.

Their mechanic just did cap rotor wires plugs can’t imagine he missed that.

Water tested it seemed to be back to normal so didn’t get into the timing