2000-2001 and 2005 Changes to Mercury EFI 2 stroke engines

**Kennay** · 11-16-2019, 01:13 PM

I started a thread a while back asking for which models of 2.5 efi would be the most desirable for an 18' center console (No promax or xs stuff, not in budget). Through my searching, I've seen it mentioned that for 2001, the EFI 2 stroke engines had some improvements, and again in the final year of production (2005).

I haven't been able to actually determine what these changes were. Can anyone elaborate? Is there a database I may be able to reference? Thanks

**kellytheaker** · 11-17-2019, 08:08 AM

I believe this is the data base - the members here do have a deep understanding . I too would be interested In the changes or improvements . I don' understand the removal of the promax from your decision making as I have read here a very durable - reliable package . The only item I read recently was top pin piston became an improvement in the 05 2.5 . I' Not the guy to educate you on the complete thorough changes made but with some patience there will possibly be some members that will set you straight on the facts .

**Kennay** · 11-17-2019, 08:32 AM

I mentioned it right where I excluded them.... not in the budget. I do wish though.

And actually, I screwed my title up. In 04 (Not 05) the engines became smart craft ready, but I have read about changes in the 2001 model year.

**Merc 2.5** · 11-17-2019, 09:16 AM

2001ish they did away with switch boxes so it changed the ignition system they also went to oring heads bout that time bout all I can think of. The top Pin pistons were for race motors 260 ,280 ,drags. I'm sure I'm missing something tho

**Capt.Insane-o** · 11-17-2019, 01:39 PM

Down draft intake, alternator, cdm ignition unfortunately with a rev limiter. Very stout motor when refit with a switch box ignition.

**Kennay** · 11-18-2019, 07:22 PM

Excellent info thanks!

Any other changes for 04/05 besides being smart craft gauge ready?

**Greg G** · 11-18-2019, 07:28 PM

Are you sure it took Mercury until 2004 to make a fishing 2.5L 200 EFI with Smartcraft?

The reason I ask is if memory serves BOTH the 2002 225X and the 2002 200XS came with SCM.

**Kennay** · 11-18-2019, 08:09 PM

Shows how clueless I am in regards to the topic.

I have been searching a ton, and I think what I am understanding is 01-02ish came with the "Basic"? Smartcraft and the 04+ has the more detailed (Though I have no clue what it involves) capability?

**Kennay** · 11-18-2019, 08:30 PM

And again, I could be totally off. Someone feel free to school me

**Kennay** · 12-17-2019, 07:36 PM

Little update. Have been doing a ton of searching and looking at parts diagrams.

It appears that in 2002, Mercury added an alternator to the 200, and in 2004, they switched from the 2.5 block to the 3.0 block. Weight went from ~400 to a little less than 500.

**Capt.Insane-o** · 12-17-2019, 09:51 PM

Yes and No.

**Greg G** · 12-17-2019, 10:06 PM

I could've sworn you could buy a 200hp 2.5 litre in both Carb and EFI in model year 2005. I thought that was the last year of new for Merc in the US market.

**Capt.Insane-o** · 12-17-2019, 10:32 PM

Yes..and once retrofitted with proper parts made a kick ass little motor.

**Kennay** · 12-18-2019, 09:45 AM

After some googling, it appears you are right! One could get a 2.5 or 3.0 in a 200. Interesting. This is good stuff, and I hope one day some dummy like me who wants to know this stuff stumbles across this thread and doesn't have to ask.

**XstreamVking** · 12-18-2019, 09:52 AM

I really like the late 90's motors. (ff blocks) I have several and they are super reliable. Find a good corrosion free 2.5 200 EFI and put all new electrics and fuel pump on it, clean the injectors, and you will have a great engine for cheap.