2010 Mercury, F80PT EFI, 4 stroke, 1.73L, increasing power

[ivan_zg]

Dear all,
I have recently bought Merc 80HP 2010 EFI 1,73L ("produced in USA; customized by Brunswick Belgium") and as I can see (youtube movies/tutorials and manuals with parts list) it is the same as 75/90(115) for US.

I have already read about two ways of converting 75 to 115 : The first one is by sending ECM for reflashing (follwed by removing restrictor plate/washer) and AFAIR the second one includes only ECM swapping(with 115 HP one, of course) and restrictor plate removing.

If I only change existing ECM (897727 22T - according to part numbers EU version with my SN should be 22T) with one used on 115 HP (897727 21T) will it work without any modifications (I have replaced AirFilter and there was no restrictor plate in my motor)? Any issues/incompatibilities could be expected since existing ECM (80HP) is for EU and desired one (115HP) is for US market?
If this "ECM swap" will work I would like to hear your opinion (I havre really no experience)... Is it better option than sending it for reflashing (cause it is at least $300 cheaper and I still have my working ECM as a spare part or I can sell it)???


Which is the easiest way to find out gear ratio of my engine (only 115 should have 2.07 while all other should have 2.33) without disassembling it? Currently I have 13x19P propeller and as far as I know from previous owners it is stock propeller BUT what I noticed is that with this setup (13x19P prop; 5.1 m fisherman boat which weights about 750 kg; 2 persons and 100 kg extra load) I cannot reach more than 5200 rpm while speed is cca 30 kts. Is this then an "overkill" for this motor since declared max rpm should be 6000?

Thanks in advance..

 

[beerturbo]

Howdy

Ive recently purchased the 75 Hp mercury 1.73l motor and have ended up reading your thread,

From what i found with Parts diagrams there is a 75/80/90 and 100 hp versions of this motor that were basically the same, minus the restrictor plate in the lower models.
The 115 motor has a different set of camshafts, presumably larger lift to allow more air.

I have spoken with a few places about getting the 100 hp ecm tune flashed and this does not seem to be a problem, some places have suggested using there 120 hp custom tunes etc, but i think id feel more comfortable with the 100 hp stock tune.

at he moment ive been looking for a secondhand 90 or 100 hp ecm to try on my motor, but they dont seem to come up much, so i think ill end up having the ECM re flashed.

With regards to you prop, you would really want to sort out any power upgrades before playing with the prop. You might find your 19p prob reaches max rpm once you have another 10-20-whatever HP.
But if your leaving the motor in its current config then yes the 19p prop will need to go down a pich, or even two sizes to get you closer to your operating range.

if you remove the flywheel cover and mark it with a paint pen, then remove the spark plugs, put the motor in gear, then turn the flywheel and count the rotations of the prop, you will be able to work out your gearcase ratio.

regards

 

[jimmbo]

Before one goes all Gung Ho about Reprograming, the control module, you need to a line by line comparison of the Factory Parts lists. If every part # is IDENTICAL, then and only then, will a reprogram work If there are part with differing #s, then those parts have to be changed as well