Yamaha F200 upgrade to F225?

[jjmoneysauce]

So there are articles out there about how it's supposedly possible to modify the ECU on a 3.3L F200 to make it a F225 or a F250. Likewise with a 4.2L F225 to make it a 250.

What I want to know is, is there anybody out there who has actually done this?

The reason I ask is that my boat is rated for up to 230 hp. On one hand, I'd like to put a 250 on it, but the insurance folks might not agree with that. On the other hand, I'd like to put a new 4.2L F225 on it, but that's big $, and none of my local dealers seem even remotely interested in the repower upgrade with trading in my existing motor. I'm sure it would be a different matter if I flat out bought a new 4.2L F225, but again that's just too much $ for me to throw at it.

However, if it really is possible to flash or change out the ECU to get a few more ponies out of the 3.3L, I would be interested to know in detail about it. And I don't mean the sketchy tuning kits you can find on ebay, if you know what I mean.

So, does anyone out there have any specific knowledge or experience with ECU upgrading? Is it realistically possible?

[99yam40]

You will have better luck finding a racing forum to ask that question.

Just by new decals for your motor and see if that will give it a little boost in HP

[lfarley4]

ecu unleashed and simon motor sports are doing upgrades. I just had one done on my yamaha vz 250. Starts a lot better when cold and has increase the mid range, but I did not see an increase in speed, but I told them not to change the rev limiter. ecu unleashed did mine.

[ausnoelm]

How do you expect an increase in top speed unless you either increase prop size, or increase RPM past the current limit??

[pstephens46]

Thread is a little old...

Maybe madharchod will weigh in...