90HP Opti To 125HP

[Mike Nelson]

Hi there, does anyone know if there is any major mechanical difference on these motors? My dealers mate can reflash my ECU to a 115 no worries but i figure i may as well go to the 125 if possible. any one?

 

[byron cooley]

There is more to modding the Opti than just the ECU. The throttle body also needs to be larger.

 

[Gilbert Scales2]

Byron, I agree. Also displacement needs to be changed. I checked with my techs, both said the ECU can be flashed to larger HP rating, however it doesn't make a bit of difference on the overall rating. If so everyone would be buying 100.. and making 200 out of them. Another word of caution here... if it were possible to do so, the 160 is rated for 90 HP max. If God forbid, an accident happened you are over powered... nothing would be paid for by them.



Bubby

 

[butch hannah]

i have wondered the same thing ... the 75,90,115,125 opti all are a 1.5L and have the same cc,same bore & stroke and same weight and i have wondered if it was just a cpu controlled difference in fuel pressure and timing that make the difference in the hp output



so to me its gotta be kinda of simple to turn a 90 opti into a 125 opti



we need a mercury tech to give us some info on this

 

[byron cooley]

The 1.5L Opti's all use the same parts including the block and exhaust tuner except the 75hp. The only difference is ECU, throttle body and gears. I have been all over the microfische parts blow up's. I have a freind with a merc dealer and spent hours cross checking part numbers.

This may not be true for all Merc engine families but it is for the 1.5L. So good mods are easy but expensive for this engine family - $1400.00 for the ECU and nearly $500.00 for the throttle body.

 

[Mike Nelson]

So you are saying that the 90Hp and the 115HP are identicle and i could get my firmware flashed and have a 115. however to go to the 125 it would require extra parts to be purchased, hense making it too much to bother.

 

[byron cooley]

I dont know about the 125hp as it was not out when I did the research. The 115 and 125 use a 2.07-1 lower and the 75 and 90 use a 2.33-1 lower unit. Also Simon Motorsports says that the 1.5L will reliably run with the limiter bumped up to 6200rpm and 120-130HP with ECU mods. Simon Motorsports will do the ECU mods for $500.00. Sounds like a great increase for the money.


http://www.simonmotorsports.com/ecu/optiecu.htm