E-Tec tuning question

[Mr.Rude]

Can a 200HO be tuned to 225 or 250 output? Are there port timing differences or is it all in the computer program?
Just had a conversation with a Merc dealer and he said they tune up the smaller hp Merc's often, like a 200 up to a 225. Anyone know of this?

[Baja16]

The 200HO block is different than the 225/250 block. But to answer your question, no. Once a model number is saved into an E-Tec EMM that EMM will only accept engine maps for that model number. So once it been programmed for a 200hp it will only accept 200hp maps...

[Mr.Rude]

So even replacing it with a 225 EMM will still not show a benefit in an any way?

[racer]

As mentioned exhaust porting is different. When a new emm is purchased it has no map in it, you down load from your old computer to transfer to the new one, this also keeps injectors matching.

[seahorse]

Even if you put a 250 HP EMM on a 200 HO engine, it would run very rich and not produce its original power due to the cylinder porting differences.

[baja200merk]

200HO exhaust port is about .050 lower then 250 and the Cyl head is different also. Easy swap if you have all the parts and the powerhead is apart.

[Mr.Rude]

I don't have an engine yet, just seeing what the possibilities are if I decide to get a 200HO.

[wicheckmate]

Just put a 225HO EMM on a 200HO powerhead....... Runs like a champ.. pulls like a champ.. I wouldn't say its any better or worse.

[racer]

Remember the computer needs to have the injector flow information for those on the engine. When replacing and emm it also needs to be timed.

[wicheckmate]

yup, matched the injectors but kept the 225ho mapping...

[Speed Jr.]

yup, matched the injectors but kept the 225ho mapping...

Cheater!!!!! Haha...... That's a good running motor Brett. Nice seeing ya up at 3 Lakes!

[wicheckmate]

you to Larry! love that Classic 22 you brought up... Thing was sweet!.. yeah she don't run to bad for a 200 HP motor