2017 gs22 H5 stumbling/stalling. Perplexing two mechanics

[MONTANAJACK]

Starts. Runs rough. Frequent stalls. Will not rev above 1650 rpms. Only code was exhaust manifold exhaust temp.

Dealer had for 2+ weeks. (young mechanic) After doing next to nothing for 2 weeks, they ordered a new fuel cell with no real explanation why and overnight shipping. Felt like they were just guessing. Since I am second owner and not covered by warranty I moved boat to an independent boat mechanic with more experience.

Independent mechanic says fuel pump tests fine. Checked 02 sensors. Fuel sample clean. Ran off alternate fuel tank with same results. Raw water impeller checked and fine. Says plug wires dont test good so replacing them now but have now lost nearly a month of summer and hoping for other high probability suggestions to check since I am not confident plug wires will be the solution.

Thank you!!
Jack

[Kmayotte]

Sorry for your troubles. Are these not Nautique mechanics? Might want to get them involved so they can be in direct contact with PCM.

Why are you not covered by warranty? I'm a second owner and got the duration of the warranty (you have to pay to have it transferred).

[MONTANAJACK]

Thanks. The first was but lost my faith as described. (another recent/worse/convincing story of incompetence at same dealer by owner of my old boat). Sadly/stupidly- I was not aware that I needed to do something to transfer the warranty when I bought the boat used. The automotive industry obviously doesnt handle warranties that way and this was my first boat new enough to qualify. By the time I realized it, they refused to transfer it as their policy is within 30 days of sale.

[MONTANAJACK]

Also... I have left several voice messages with PCM but they dont appear interested in direct owner support or at least not the timely kind. Hope I can correct this statement....

[core-rider]

Starts. Runs rough. Frequent stalls. Will not rev above 1650 rpms. Only code was exhaust manifold exhaust temp.

Dealer had for 2+ weeks. (young mechanic) After doing next to nothing for 2 weeks, they ordered a new fuel cell with no real explanation why and overnight shipping. Felt like they were just guessing. Since I am second owner and not covered by warranty I moved boat to an independent boat mechanic with more experience.

Independent mechanic says fuel pump tests fine. Checked 02 sensors. Fuel sample clean. Ran off alternate fuel tank with same results. Raw water impeller checked and fine. Says plug wires dont test good so replacing them now but have now lost nearly a month of summer and hoping for other high probability suggestions to check since I am not confident plug wires will be the solution.

Thank you!!
Jack

Is this while under a load in gear or just in neutral? I'm assuming the plug wires not testing good meaning high resistance read with a meter? Has a compression test been done on each cylinder? What about testing spark at each plug and testing each injector to make sure they are all firing? I would have a look at the plugs to try and identify a cylinder with issues as well.

[MONTANAJACK]

Thanks Jason. It is running poorly both neutral and with throttle. Correct about the plug wires though I admit it was surprising to me with only 123 hours that factory plug wires would be bad.....I will add your suggestions to my list to ask my current mechanic about. Thanks for your time...