Optimax 200 HP Upgrade to 225 HP ?

[grahamf]

I have a Mercury 200HP Optimax (2001 year) which has run about 100 hours only. It is mounted on the back of a monohull sportsboat from a a UK manufacturer called Ring Powercraft. The boat is 21 ft, total weight of boat and engine approx 900kg

I understand that the 200 HP and 225 HP Optimax engines share many components, firstly is this correct ?

If this assumption is true, is there a way of 'upgrading my engine' to a 225HP spec ?

[1BadAction]

Buy a brand new 225, it will be easier than converting, Cheaper too... while your at it you can go for a 250 they all weigh about the same.

sorry, i know thats not what you wanted to hear.

[pmgoffjr]

Other than a set of composite reeds, forget about it, there isn't squat you can do or are there any parts available to mod a Optimax.

[merklebob]

the new 225xs is a 3.0l iter where the 200 is 2.4.

[pyro]

Yeah right, you mean the 2.4 that hasn't been made since 1991?

??? <::::::::::## ~~~ smoke some more...

[DarthVMAX]

How come so many people are getting the 2.5xs (2.5L 225xs) and the 250xs (3.0L) confused???? And where in the world does the 2.4L enter this picture???

(I know, it DOESN'T! )

[C-Webb]

I think merklebob is talking about the newest Pro XS 225 and he is right, it's a 3.0L...

[steve]

The 200 Opti is a 2.5 , the 225 is a 3.0L. YES you CAN mod the 200 to make it a 225 2.5 L. Email me and I will walk you thru it. Basically porting, heads, exhaust outlets enlarged, rod slot and a few other easy mods will net you 225 easily. There are not that much different then the 200 carb or Laser motors.

[merklebob]

my mess up my 2004 200xs is a 2.5 l not a 2.4 the 225xs is 3.0l and there is a 2.5xs 225 hp that is 2.5l.

that's very interesting. if the fuel economy [7.0mpg max] is like my 200xs that could one very interesting motor.

[pmgoffjr]

Whoa..
The 200 Optimax IS a 3.0L motor, NOT a 2.5, unless you mean the newer 200XS. He's got a '01 Motor which is a 3.0L.

And If you think grinding a little port work won't confuse the snot out of the ECU, think again. Too many pumps and sensors have to work together to start monkeying with one, you'll set off the other. Already been there, already done it.

[steve]

I stand corrected. These were 150's and 175's . Sorry, the 200 is a 3.0L. We have modded a few Opti's and its not that hard though. The ECU can be richened a bit but its already got a safety margin from Merc. Increasing the fuel pressure is the way to do it or you can also modify the air temp sender input to the ECU to richen the fuel curve. The porting is nothing extreme and the motor behaves like a 150,175 at the bottom and revs higher to make the extra hp. We like the setup of std Laser 200 being modded better then the 225 ProMax for a bass boat on the non Opti motors as well. The exhaust port height combined with the sharp turn going into the 3 boost ports limits the rpm of the 200 as does the exhaust cavity. The 4 petal reeds still allow the motor some nice bottom end torque . You can leave the exhaust windows smaller if you need even more bottom end but it will kill the top a little. Yes, you have a 3.0L, but I am sure it can be modded easily just like the 2.5's and richening the motor to support the extra hp is not all that complicated. Programming the ECU would be the best way, but there are other ways that will work as well.

[DarthVMAX]

Sorry, I didn't know there was a 225xs 3.0L

My bad

[sosmerc]

You can always go to a site like dougrussell.com or Merc's Parts Express and compare part numbers on such things as powerhead assemblies. I have not yet checked to confirm, but my guess is that the only difference between a 2001 3.0 litre 200 Opti and a 2001 225 3.0 litre Opti is the ecu part number.
There are lots of ways to modify such things as port timing, compression, reeds, weight and balance of components, gear ratios etc., but unless you can also "adjust" the PCM in concert with these modifications, you are asking for trouble.

[sosmerc]

http://www.mercuryremanufacturing.co...86&chartId=253

This chart might help. (and I see the part numbers are NOT the same for the 200 Opti vs. the 225 Opti in 2001. I don't know what the differences are, it might be just tighter heads, or different reeds, or more substantial differences such as port timing....or some combination of the above)

[MERCMAN]

the block is the diffrence (ports etc) , the only thing about the ecu upgrade is supplying the extra fuel for the extra h.p. everything else is the same. all the parts are the same other than the ecu fuel curve and the block.


unfortunately at this time the only engines to replace our high perfromance motors for 2006 will be the 225 xs and the 250 xs. the 250 xs is an awesome motor though! it is comparitive to the promax 300 not the x. its a stout motor!