Let me know what it is becuase I have been trying to troubleshoot the exact same problem on 496 port motor but I have bravo 1 drives

the faster I go the more off the throttles get

Did anyone, as yet, identify the problem and what was the fix? I'm having a very similar problem with a 496. Thanks...

[QUOTE=oz boater;3128267]Any 496 experts that might be able to help? I have two weeks of warranty left and something is not right.
/QUOTE]

I hope you have all this documented ...Merc should fix this ....

My direction would be fuel, if the fuel preasure stays good while running then start looking at the injectors. It might be a good idea to send them to a shop that can bench flow check them, check the coil resistence, and ultrasonic cleaning. If the computer did not show anything and you have good spark on all cylindrs then I would start looking at fuel flow. Fuel injectors have been a big problem at my shop.

what about a Clogged pickup?

Mine is still in the shop ranking up the hours they still havent come up with anything not going to be a cheap bill

I had the same exact problem, did everything recommended.

What I don't know is did you replace the fuel filters, that was not my issue, but you should.

My isssue was a "ever so slight" plug wire crack. It never showed up in testing, 1st inspection, etc. I even changed all plugs. Finally I decided just to swap out all the plug wire and BANG, problem instantly solved. No codes, no errors, etc...ever showed up.

You may have a different issue, but just in case, replace the plug wires....cheaper than spending 2 more hours at the shop. You can get them from Ray at Raylar.

Same brand fuel separators? Fuel flow consideration.

Inline filter been changed lately?

Pop out each injector and tap out the grit that tends to gather in each.

How much useless crap do you have stored in your boat?

Have you swapped aroud the ECU's yet as suggested?

No two motors are alike. Can be up to a 10% power difference between any given two.

If it was a plug wire wouldnt it show it in the plug