2.5 efi

[Vecman]

Just purchased a 96 200 2.5 efi Merc. Motor is in perfect shape,
Only about 500 hrs on it. Compression is around 110 on all cly.
What can I do to bump up the power a little. Thought about
tuner, removing the liner , and some different heads. I know
I'll have to have the ecu reprogrammed. Who is the best at
reprogramming the ecu. If I bump compression up how do I
compensate the fuel? How many rpm's will this motor turn
before the fuel system be damaged or something else let's go?
Any info would be great!

[Jay Smith]

Vecman,
Compression increase is always a good and enexpensive way to boost power on outboards. Also the inner liner can will pick up the motor moderatly. It will be louder and that sometimes make one thing it is going faster :) .

If you raise compression to a safe pump gas level ( MAX 145 lbs ) your brain may need to be richined up a bit but it has alot to do with geographic location ( altitude ) , weight of boat , and prop size used.

The more a motor is lugged down with such as heavy hulls and big pitch props the richer the motor will become and the less the brain may need to be sent to be richened. Performance Plus Marine is a good choice in getting your brain calibrated if needed.

Good luck and good boating !

Jay @ JSRE 1 281 576 5088 CST

[Still crazy]

Jay,what would you estimate the net gain in HP to be from the aforementioned changes?

[Jay Smith]

Thats hard to say but I would guess 20 to 25 HP on a motor with low compression and a choked down exhaust.
Thats an estimate only !

Jay @ JSRE