Pontoon Boat & Deck Boat Forum

I'm sure this has been discussed, are there any negative side effects flashing the ecu and making the 90hp a 115hp. Is it worth the $650. What kind of performance improvements should I expect?

I am also interested in this upgrade, i contacted Simon motorsports in early summer to inquire about it and was told that they did not have programming done for my motor, it would be about 2 month before it would be done, i called them last week and got the same answer, still not done.
There is a couple posts in the bass boat forums that have had this done and they were happy with the improvements.
They do have a good reputation for what they do. hopefully they will have it done by spring.
I am thinking 3 mph improvement, they claim to upgrade to aprox 118 hp

I am very happy with the work they did on mine. I didn't gain that much speed, about 5 mph. But the fuel consumption and hole shot noticeably improved. You really have to stay on the boys at Simons. My 10 day turnaround time turned out to be almost a month, but that was alright, because I did it off season. My fear was that it was lost in the mail. My 85 HP burn actually netted me a little more also. It dyno'ed out at 316 at 6600 rpm's on 93 octane. I propped it to run 6200.

I wonder if this would work on our 150 Yahama HPDI, from what I have seen the 175 is nearly the same thing.

looking at their website it looks like the are more focused on the larger 300 hp and racing motors than our little 90 hp barge motors
i will keep on them thru the winter. I would not take my boat out of service in the summer for this upgrade as the summers are too
short up here anyway.

For a Yamaha, these guys are the best. They were working with Simons on re-flashes, when I was talking to them about swapping my Mannies Etec for a 250 HDPI. Not sure if they got it done. Eric burns the bigger HDPI's. But for making a Yammie bulletproof and fast I would call Wayno! http://www.shop.hydrotecmarine.com/ They are Yamaha Gods!!!

I have a Yamaha 90hp 4-stroke. So what all does this require to do the flashing of the ECU. Taking my 90 to a 115 to get a couple more MPH and better fuel economy sounds like a great idea.

Contact Eric at Simons Motorsports. 760-440-9334 tell him what you want to do. Remove your ECM and send it to him. He will reflash it and send it back to you. Like I said, I have to run 93 octane to achieve full gain. But even running 89, I am still at 285-300 range. He can explain all of this to you, when you call.
Have fun with it!

I have a 2006 Mercury 90 fourstroke. Are there any disadvantages of doing this?

Only one I can think of is you MAY need to re-prop to compensate for the RPM gain. But I live for that stuff! It will do nothing to your L/U or mid section. The timing and fuel trims are smoothened out but not leaned. Basically, you are interchanging a 90 ECM for a 115. Best way to put it, I guess.