Newbie 3.0l merc questions

**vbtravisd** · 03-16-2017, 08:09 AM

Hey fellas... I have been on a few forums asking about my (what I believe to be a...) 1995 Mercury, 225hp XRi, EFI, long shaft, 2 stroke (picture attached). Everyone pointed me to S&F for info on mercs! So here I am and I hope you have patience for my new kid questions.

A little background, I am an engineer by day... backyard wrench turner when the wife and daughter allow. I am comfortable around engines and projects in general. Well, I picked up a fishing boat the other day with the above mentioned outboard bolted to the back. Guy said "the motor is trash and won't do anything when the key is turned"... It does appear that the powerhead is seized. But when I pulled the cowl, the powerhead looks practically new! And it appears to at least had the block bored (030 paint marks). There are barnacles all over the lower unit, and when I went to turn the prop the lower unit spit a chunk of the housing. So I imagine I need a midsection and lower unit at a minimum. I have tried to search all over the interweb for info on this thing... so here starts my questions:

Is this in fact a 95?
Is the 3.0 a good motor?
What is the interchangability in parts between the 200s, 225s & 250s? I have found a 2002, trim/midsection/lower unit off an 225 optimax and that would be a good swap if I can break the powerhead loose and if it will bolt up to this outboard. Does anyone know if these 2 will bolt up?
Is there a potential or benefit to an oil pump bypass and just mix gas?

I think that's all the questions for now... I am going to pull the covers and see if the cylinder walls are all scored up... blast a bunch of ATF or PB blaster in there and see if I can get the flywheel to turn. I appreciate any info you guys can pass my way.

:cheers for beers:

Travis

**FORBESAUTO** · 03-16-2017, 10:40 AM

I would remove lower unit 1st and see if motor will turn, possible lower is locked up and not motor.

**vbtravisd** · 03-16-2017, 07:44 PM

If the lower unit were to blame... would the prop be able to spin freely in neutral?

**FORBESAUTO** · 03-16-2017, 08:05 PM

Yes, your only turning the propshaft in neutral. The gears and input shaft are not turning. Hopefully this will be your problem and motor is Ok.

**vbtravisd** · 03-16-2017, 08:10 PM

Thanks for the info, good to know! Boat is at a buddies house till I unload my current boat (wife said I couldnt park a fleet in the backyard) ha. Otherwise I'd walk out back and drop that lower unit right now.

**H2OPERF** · 03-16-2017, 08:32 PM

Try rocking the flyweel by hand, you can usually tell a few things, if it is solid as a rock and will not move the slightest little bit its probably trashed, if it moves slightly this usually means its piston frozen and not crank frozen which could be a good thing bottom end may have some good parts. like was said above pull the lower you never know. Dave

**vbtravisd** · 03-19-2017, 06:40 PM

Welp, got the boat back to my house and took a good close look at the engine. Lower unit dropped and the flywheel still will not turn! I took the heads off and looked down the cylinders, they actually look good! No scoring, still have some cross hatch! 5 of the 6 pistons have some wiggle, one of them has a good amount of rust all the way around it. To me, it still looks like it has some potential.

So would this 95 XRi bolt up to a 2002 opti mid section and lower unit?

**vnemous** · 03-19-2017, 08:27 PM

yes you will have to plug the fitting on the exhaust plate for the air compressor. count the splines on you current driveshaft, there was one year with different splines I believe. JMO

**vbtravisd** · 03-19-2017, 08:31 PM

Thanks for the info man... I grabbed a couple of beers and searched through a couple hundred threads on here talking about interchangeability. I found a bunch that said it would work, a couple that said it wouldn't... but those were a lil older threads.

I have a 13 spline driveshaft, seems like that is a pretty common spline count.

**vnemous** · 03-19-2017, 08:46 PM

yes than you will be fine. my personal 1998 250 efi is on a newer opti exhaust plate

**flabum1017** · 03-19-2017, 09:14 PM

You said one cylinder is rusted up..... try soaking it with PB Blaster and whacking it with a 2X4 and hammer ( 2X4 on the piston) Maybe just stuck on one cylinder and easy rebuild.

**vbtravisd** · 05-25-2017, 11:59 AM

Welp, I am bringing this thread back. I hate it when threads get started but never finished or no one knows what happened. By hell or high water I am going to rebuild this thing or blow it up trying.

So I gave it hell for a couple of days, soaking it with PB and using a BFH and a 2x2. Nada... I am going to go ahead and get the motor off the back of the boat and in the garage (hopefully this weekend). I think an application of heat is next on the list of things to try.

But I have been trying to keep some forward momentum. I grabbed that Opti 225 XXL mid and lower for $350. Had to drive a couple hours to get it... and I half assed strapped it to the back of my wifes car because 30mpg vs the 15 my truck gets... but I got it home. I made a stand, bolted it up. The thing is in perfect shape! Looked at the lower unit oil, looks clean, changed all the zincs and its sitting waiting for a new powerhead.

This is where I am flirting with disaster. I have combed through easily 500 threads here on S&F... I have seen where some guys are getting almost 300hp out of these motors. I will be pushing a 4k pound boat (dual purpose family and fishing) with this thing. The extra HP would be nice, but I just want a strong reliable motor. But since I am rebuilding it and have everything apart... I am starting to look for some things that I could do to help the life of this thing. What do you guys think? Should I look for better reed and cages than stock? Flywheel options? Poppet diverter? Or just build it back to a stock motor?

**vnemous** · 05-25-2017, 01:23 PM

If its got metal reeds lose them for synthetics from Chris Carson Marine. Other than that you want reliable keep it stock. See in post #8 I said one year with a different crank spline? Well lucky us we just got a drop on to change on a customers boat and it was the one year with the 2.5 spline. Fuller had to change the crank in the motor and the customer need it for an offshore race that weekend.

**vbtravisd** · 05-25-2017, 02:34 PM

10-4 on the metal reeds.

Yeah, I thought ahead enough to take the long shaft coupler out of the old lower and take it with me to verify. That is some buzzard luck to have the 1 year that was wonky...

**vbtravisd** · 05-30-2017, 07:32 AM

Got the outboard pulled from the boat. Powerhead came off real easy! Found a paint mark under the alternator... This engine was rebuilt 9/10/2012. Overall things look in awesome shape... except for that stuck piston. ha!

I am putting together a list of things to change while I'm at it. T-stats, impeller, poppet valve, plugs... anything else I should be looking to replace?