250xs -- 300xs

[helios2001ve]

HI..... CUESTION.... MERCURY 250XS + 300XS ECU = 300XS ?????? DIFFERENT ONLY ECU??????

250XS + 300XS ECU= 250XS AND 300 HP ?????

[.....]

i belive the 300 is stroked to a 3.2.

[merccoop]

^ Correct, the 300xs is a stroked 3 liter = 3.2 liter.

[R.grover]

yer it is 3.2L few other small things to

[kcline]

I'm confused, I have been told that changing the computer will make a big difference, also was told that was the only difference in the motors. Maybe the year makes a difference, I'm talking of a 2005. Any help would be appreciated, very confused, want the dependability and would also like the extra power.

While we are on the subject of 250xs. I have a torgue master with water pressure problem when jacking up, any suggestions on mods to improve this. Thanks for your help. Kelly

[merccoop]

Yes, ALL 300xs's are 3.2 liters. I have no clue if it will even run at all well with a 250xs ecu. I would assume it wouldnt based on my experience at Mercury. The tune on those ecu's is for a specific set of hardware within that motor. Since the 250xs and 300xs are not identical motors, I would assume it would run like piss.

Maybe the people you are talking to are speaking about the Verado and getting them confused. The 6 cylinder verado (minus the 300 and up) can swap ecu's without problems.

Maybe Stinky can chime in on this, he would be able to instantly clear up any confusion.

[Markus]

I'm confused, I have been told that changing the computer will make a big difference, also was told that was the only difference in the motors. Maybe the year makes a difference, I'm talking of a 2005.

There was no 300XS in 2005. Whatever you were told, it was wrong.

[kcline]

Okay I'm understanding you cant change the computer and make it work, I really thought the 300xs was a 3.0 litre also. (my bad) So is there any ideas to bring up the horsepower without going into the motor and doing major work? Any thoughts on the lower unit, I had heard an idea to put possible screw in the top holes. I appreciate all the help ,and knowledge on these treads. Thanks Kelly

[FAST RALLY SPORT]

i'm Confused, I Have Been Told That Changing The Computer Will Make A Big Difference, Also Was Told That Was The Only Difference In The Motors. Maybe The Year Makes A Difference, I'm Talking Of A 2005. Any Help Would Be Appreciated, Very Confused, Want The Dependability And Would Also Like The Extra Power.

While We Are On The Subject Of 250xs. I Have A Torgue Master With Water Pressure Problem When Jacking Up, Any Suggestions On Mods To Improve This. Thanks For Your Help. Kelly

Maybe The People You Are Talking About , Were Talking About A 300pm Ecu, Or 300x Ecu. Bobby

[R.grover]

Mate would love to no what u can do to the xs range as i have 250xs and 300xs i have only seen and pcm/ecm upgrade for 225 opti that takes it to 250hp thats from simon motorsports

[Simon]

The only thing I recommend on the 250xs is my lightened flywheel. I can raise the rev limiter also but they do not make more power up there.

[dkramer]

Helios,
Depending on how fast you are running, you may want to have a LU pickup / nosecone put on. A buddy of mine tapped and put screws in a few of the top holes on his Torquemaster and it helped. I myself have a 250xs with a Torquemaster LU that is coned and I have 15+lbs jacked high to the sky. Some people say a cone is only helpful if you are running over 80mph but I have had good exp thus far. Just my 2.

Eric,
What advantages does a lightened flywheel have on the 250xs? Does having the injectors mapped by Brucato help out at all from your experience?

Dave

[R.grover]

eric i see you have ecm upgrade for 300xs what do u raise the limter to?
and how much can u take out of the flywheel what do yours weigh?
thanks heaps

[Simon]

dkramer, The flywheel will give you a better hole shot,acceleration,and in some cases a little top end. Some people are able to run a bigger prop and gain top end.

R.grover, On the 300xs I can raise the limiter to whatever you want. The flywheels are 14lb's stock, I take 3 pounds out of them so they still idle correct but accelerate better.

[kcline]

Simon, Do you have replacement flywheels, or stock one has to be sent to you to be cutt? ty Kelly