Axis Wakeboard Boat Forum

Cross posting because the DIY forum seems to be pretty dead - sorry if not allowed.

New to me 2016 Axis T22 with a brand new Monsoon 350 - prior owner somehow fried his, sold it, and the shop I bought it from replaced it. After buying and babying it for the 10 hours and getting service, it ran great. Minor issues with the surf gate fuses blowing but swapped them out for breakers and it's been running great, until this past weekend.

I ran the boat a few weeks ago with no issues. Put it up on the lift, got busy with life, came back this past weekend to take it out. Saturday I fired her up and got the red MIL engine light on the dash and the SERVICE ENGINE warning. I went into the onboard menu and reviewed fault codes - it said there were none. Some quick research said it sometimes happens, don't worry, the boat will be fine and it'll go away on restart. Took her out for a little bit and other than the SERVICE ENGINE buzzer every 5ish minutes, it ran great.

Sunday fired the boat up, no code, no issues, no MIL light, no alarms. Surfed with a few friends for a few hours, then went to cruise down the lake to get lunch. About 20 minutes into the cruise, the MIL and SERVICE ENGINE warnings came back, still no fault code. I ignored it.

Cruising about 4500rpm and all of a sudden the boat starts to lose power. It was a gradual drop in RPMs, from 4500 down to idle in maybe 6-8 seconds, like I was intentionally trying to slow the boat down, except I hadn't touched the throttle. I put it into neutral, scratched my head, then gave it power again and she went right back into action. The same thing happened 3 or 4 more times before we got to our spot. I poked around in the menu - nothing. Looked around the engine compartment for any obvious signs of issue - nothing. Water temp was sitting right around 158-162 during cruising so within normal ranges. Oil pressures looked good on the display. Boat sat for maybe 2-3 hours and then we started the trip home. Same issues - MIL, SERVICE ENGINE, and it dropped the RPMs once. After that, I set the speed to just under 4000rpm and she stayed steady the whole way home.

The engine has less than 20 hours on it. Boat only has 365ish. No knocking, sputtering, or any other obvious signs of engine issues. I keep the batteries on a NOCO Genius GEN5X2 tender while it's up on the lift. Only ever run in fresh water. Ran perfectly fine the last time I had it out, no issues or codes whatsoever.

Any thoughts or places I should look? I pulled it and took it to the shop I bought it from - they are a Malibu / Axis dealer, but said they won't be able to flash the ECM if that's the issue because they aren't a PCM dealer, so even though they installed the Monsoon 350, they can't work on the software side. They haven't been able to get back to me if they've found any issues or identified what's wrong. I've only had the boat on the water a few months since buying it so I'm not thrilled to already have it back in the shop for this mystery issue. Hoping the rest of the season isn't a wash...

Thanks,
-Bob

They still have the boat? I’d take it to a dealer that works on PCM engines in your area instead. The engine has some type of warranty from PCM I assume? I had an engine replaced in the past(different brand) and the replacement engine was burning oil at an unusual rate. The engine was replaced by indmar. I’ve found that some mechanics are good at replacing parts. Some are not as good at diagnosing issues. You need less of a part replacer mechanic.