Yamaha 4.2 V6 Offshore / SHO upgrades

[FOURCED]

Has anyone swapped their ECU or re-flashed one from Simon with anything to report? Seems all engines - (hardware) is the same from 200 - 300HP. Ignition Timing would be the only obvious parameter that would significantly affect HP but I suppose they could be "starving" them to some extent with cam timing. Planning an upgrade on my 250 offshore and will report results. I suspect I will have to sync the new ECU to DEC control box. Any thoughts or input?

[Lockjaw]

Pretty sure Wayne Worthy at Hydrotec can handle that for you. He's done some work on them.

[VectorPat]

Pretty easy to control horsepower when there is an electronic throttle valve

[FOURCED]

I spoke with Wayne yesterday and He promptly referred me to Simon. I got the impression he's still got pre-mix running through his veins and I certainly respect that. As soon as he figured out it was a four stroke he couldn't get off the phone fast enough! LOL VectorPat - I don't think they are using the throttle to limit airflow because If I understand correctly, the SHO versions operate the throttle blade directly with the cable. I have read about the modern, Very High compression car engines limiting peak cylinder pressure with the electronic throttle blade to allow 12-13 to 1 CR on 87 octane. I suspect they are closing the throttle some near peak torque and then allowing full throttle to ramp in after the torque peak. I don't think the outboards have reached that level of technology yet but surely it is around the corner.

[FOURCED]

VectorPat is right, at least on the offshore DEC version. The ECU gives full throttle on acceleration then reduces throttle angle from ~80 degrees to ~50degrees with 100% throttle request. The parameter it appears to be looking at - (Controlling) - is manifold pressure. 300HP ECU gives ~80 degree throttle angle with 100% throttle request. No sync required on ECU to DEC - Plug and play. ~4 mph and ~400 rpm increase on my relatively heavy Tri-Toon.