2015 75 HP Mercury 4 stroke

[Maltesejeeper]

I installed a 75 HP 4 stroke Mercury to replace my 50 HP two stroke several years ago and overall I have been very happy with the change. I was looking to get a little better performance from the 75 and I thought about sending the ECM off to Simon, but apparently the EPA shut him down, but while researching different threads, some people mentioned removing the restrictor plate from the carb and so I did it. Being a bit of a hot rodder and gear head, I swear this really woke up this motor. Did it really help or was it wishful thinking on my part? I should mention that most of my boating is done on lakes that range between 4500 and 7000 ft elevation.

 

[QBhoy]

Is the 2015 75hp 4 stroke not an efi ? Won’t be a carb on her. Almost sure the newer 2.1l engine came out that year. Same as the 90/100 and 115, but mapping is different among them.

 

[Maltesejeeper]

Is the 2015 75hp 4 stroke not an efi ? Won’t be a carb on her. Almost sure the newer 2.1l engine came out that year. Same as the 90/100 and 115, but mapping is different among them.

Yes, it is EFI, but I read somewhere that the 75 is just a detuned 90 and my thought is they just put a restrictor plate on the throttle body and the computer will adjust the fuel mixture accordingly. So I removed the restrictor plate and the engine does seem to have more power, no down sides at all that I can tell. I know that Simon used to be able to pull 124 hp out of these motors with tuning, but I just needed a little more and I think I have enough now. I was just curious if anyone had any real info on this.

 

[QBhoy]

Yes, it is EFI, but I read somewhere that the 75 is just a detuned 90 and my thought is they just put a restrictor plate on the throttle body and the computer will adjust the fuel mixture accordingly. So I removed the restrictor plate and the engine does seem to have more power, no down sides at all that I can tell. I know that Simon used to be able to pull 124 hp out of these motors with tuning, but I just needed a little more and I think I have enough now. I was just curious if anyone had any real info on this.

Ah. Got you. So is it the 2.1 litre engine or the older 1.8 ? If it’s the 2.1 litre…they are the same engine up to 115. But with ecu mapping varied at least. Excellent engines I think. Way more than the power claimed for sure.