2006 250 hpdi problems

[ajs32]

I made a 120 mile round trip on day one of a flw tournament motor ran great day two we had 5 footers 20 min into taking it as easy as i could the motor shut down and would not run over 1300 RPM in the water it cuts out at 4000 RPM out of water sounds like its hitting the rev limiter. if you mat it either way it will just shut down i changed plugs and am getting spark to all cylinders all filters have been recently changed and took off lower unit to check exhaust tuner and impeller computer is not showing any codes but says 2-3 cyliders are not firing but i see good spark when hooked up to plugs
PLEASE HELP

[Pacer]

What do the plugs look like on the two cylinders that arent firing? Are they the same color as the others?

Can you do a compression test? If you don't have a tester, pull the lanyard hold your thumb over the holes and see if you have no compression on a cylinder. This can tell you if you've got a damaged piston.

Have you drained the filter, and vapor separator tank. You could have sucked up some water.

Could it be in limp mode for something like low oil in the engine tank?

Hope you find that its something simple. Post what you find so I can check my 225 and make sure I don't have the same problem.

[Charlie206]

Always start with compression test. One other thing you might check, that engine idles on 4 cylinders until you put it in gear, then runs on all 6. A switch attached to the throttle linkage where the cables attach to the engine lets the computer know you have put it in gear. Meter that switch to insure it is working. There are two switches there, the other is the neutral safety.