2006 38 sundancer 3200 rpm

[Richey rich]

So I have a friend who just purchased a 2006 38 sundancer with 8.1s HO’s. The problem he is having is that he is not able to get his port motor above 3200 rpm’s. The weird pet is that while underway sometimes it starts to reduce to 3000,2900, Down to 2600 rpms. Also sporadically he will lose all of his gauges almost as if it is going to completely power down but the motors still run. And then within a second or two it beeps and everything comes back. But was previously in salt water and is now in freshwater. I’m thinking it Hass to be something electrical and not mechanical but we can’t seem to figure it out. After sitting for a bit it will get up to 3200 again but not to far and it starts to lose power again. Also he is getting surges in rps… so when he is idling along and 800 rpm that motor will surge to 1200 then down then up and back down again. While he was cruising yesterday at roughly 2800 rpm (all he could do) suddenly the boat surged and was cruising at 3200 again. Any advice? Where to start?

 

[Stee6043]

Silly question but did your friend have a survey? Or was it running fine when he bought it?

My first stop would be to a marina with a diagnostic scanner. I'd imagine the engine is throwing some codes when it beeps?

What have you guys done so far? The surging and low WOT RPM sound like it could be fuel related? But the electrical "power loss" sounds strange.

 

[Richey rich]

Silly question but did your friend have a survey? Or was it running fine when he bought it?

My first stop would be to a marina with a diagnostic scanner. I'd imagine the engine is throwing some codes when it beeps?

What have you guys done so far? The surging and low WOT RPM sound like it could be fuel related? But the electrical "power loss" sounds strange.

Mercury mechanic came out but didn’t spend much time with it, he did scan it and found no codes. Vessel view does not show any alarms as well. I originally thought fuel also, maybe injectors, plugs or coils,something along those lines but the gauges shutting down throws me off. Could be two completely separate issues and not related I guess. The boat was surveyed and sea trialed and seemed to be run fine, but again sometimes it does so maybe just caught it on a good day.