2011 SN200 ZR409 Power Loss

[DoubleABuck]

My SN200 with ZR409 has around 310 hours. It has been running great all year long. Suddenly, while I was pulling my wife skiing, there was a subtle power loss. The boat surged a bit and continued to lose power. Wanting to prevent damage I pulled back the throttle. Needless to say my wife was a little mad that I had stopped mid ski. The boat idled perfectly. I put it into gear and it ran as it always does. I decided to try to throttle back up and the boat came right up to speed as usual and ran great as always. (By the way, I did pick up my wife.) But, after about thirty seconds the same power/rpm loss and subtle surging began again. The boat slowly loses power with subtle surges as the power loss continues. It seems to somewhat stabilize at lower rpm, around 2500 to 3000. When this happens I power down and let it idle for a few minutes then power back up. It runs great for 30 seconds and then I get the loss of power and small surges. Oil pressure is fine, temp is right at 165 and no engine codes.

My my first impression is bad fuel or restricted fuel supply. I have changed the FCC filter and in-line filter. I've put 1 bottle of Sea Foam in about 14 gallons of fuel. I've run it for about an hour. No change. If the fuel is bad I may need to add more SeaFoam. But, what I don't understand is why the engine runs perfect for a few seconds after letting the engine idle. I've tried pulling back the throttle while running and then powering back up. This doesn't get the same result.

Would really appreciate any help or thoughts!

[Rockymtnsurfer]

what needed up being the issue?

[DoubleABuck]

Rockymtnsurfer, the issue ended up being the low pressure fuel pump. I did a bunch of searching online as well as talking with a few buddies and we all came to the conclusion that this was the next thing to try. I ordered one and replaced it myself. Very easy. The problem went away immediately. It makes sense that as the engine came up to speed and the engine began to demand more fuel, the pump just couldn’t keep up. At least that’s the way I understand it. It’s intereting you replied today. I just got the boat out on the water today for the first time this year. Still running perfectly.