On the motor forums I hear a lot of people say they flashed their Outboards to get more power just wondering if this will eventually damage the motor.
On the motor forums I hear a lot of people say they flashed their Outboards to get more power just wondering if this will eventually damage the motor.
Doubtful. The motors are all the same internally. The power is made by programming the ECU (air/fuel ratio, timing, etc.). So a 200 is the same as a 250, just with different programming. Speaking of Yamaha's specifically here.
Flashing allows you to change or adjust the system beyond the manufacturers settings for even the largest HP version and can cause issues if you exceed these limits
the most common thing I see people say is don't exceed the max RPM's but there are other settings that can be adjusted beyond a safe expectable limit
seek help if and when you decide to do this
"The handicapped angler"
The Yamaha SHO big block (200-250) is really the only one that you can do that to. They are all the same "engine" with a different ECU. You can change the horsepower and leave the RPM limiter as it is.
Originally Posted by printman71
I can't confirm this. I was told the SHO was designed for I think 400+ hp and defined. It would make sense about flashing it back up in hp. I know engines a little bit, but the rest is above my pay grade!
2014 Phoenix 721XP, 250 SHO, Bobs Action Jack, Dual Blades, 112 Ultrex, 2019 Lariat FX4 F150 Supercrew 4x4
if your yamaha motor has warranty call yamaha an ask them if you flash the motor if your warranty stays in tact .
This is my understanding....
They took the fuel mappings from the Yamaha 300hp 4.2 liter blue engine and applied them to the 200 through 250 4.2 liter SHO motors.
This gives the 4.2 liter engine 300+ hp as a baseline.
If you wanted more...
You could request the rev limiter be adjusted up to 7200 RPM (or something close to that). Testing (posts on BBC) reported the engine could continue making more horse power above the stock rev limiter RPM's. Somewhere in the 334hp range at 7200 RPM.
It's not just the HP advantage, it's the aditional power band pushing into 7200 rpm combined with the ability to spin the prop an aditional 1000 rpm. i.e. the engines power band didnt flatten out or fall off above 6200rpm. I think thats what allowed them to put up some big numbers on the top end.
There is a whole Yamaha Performance subforum you can do your own research. There were videos posted as well. I believe there are 2 primary companies who can flash the ECU with "reliable" results. There are also many conversations about warranty concerns.
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