Had enough

[Haribo]

Hi guys this is for the clever ones out there
I have a 2006 155 wake non supercharge
It refuses to rev past 6500 rpm
To date I have
Swapped out plugs coil packs oil is spot on injectors cleaned and checked fuel pump swapped from sister ski that runs perfect new ware ring and impeller (solas 11/19 sister ski runs the impeller revs to 7600) no exhaust leaks in to bilge no fault codes tps has been reset throttle body checked ski starts on the button runs perfect just will not rev over 6500 not lumpy on idle will rev on the trailer to 7500-7600 I have been through every single thing I can think of so and one any ideas if so please chip in
Thanks in advance

 

[mkov608]

When you rev it on the trailer, is the seat on or off?

 

[Haribo]

I have done it with seat on and off makes no difference also forgot to say I have had the pump rebuilt new shaft bearings seals etc

 

[skiasylum]

Sounds mechanical, did you ever swap engines. Haha, the service manual would suggest a leak down test.

 

[mkov608]

I have done it with seat on and off makes no difference also forgot to say I have had the pump rebuilt new shaft bearings seals etc

The reason I asked about the seat is, I had a ski with a similar problem. So, I used Sea-Foam spray to clean up the engine (the exhaust smokes like crazy the Sea-Foam sits in the engine for the suggested 5 minutes after application). That's when I found out my J-pipe was leaking exhaust into the hull. So the engine was starving for oxygen. The pipe was leaking at the 6 o'clock position, so I didn't see the carbon from the leak.

Before the pump rebuild, did you have this issue?

It's easy enough to pull the pump and inspect it. In the aircraft business I when someone came to me with a difficult troubleshooting issue, my first question was always "What was the last maintenance/repair action?"

 

[Haribo]

Yes had the problem before the pump rebuild the bearings were a little noisy so as a matter of maintenance and trying to illuminate the rpm problem I had it rebuilt
Thanks for your replies nice to know someone else thinking about my problem