225 EFI rebuild

[8upfisherman]

Hi all! Im starting a home project. I have a 1998 225 EFI Merc. I have worn her out and finally stuck a ring in cylinder 6. engine is not trashed and it should be a "simple" rebuild. I have built many small block chevy engines and rebuilt and maintained a jet ski my friend raced. Im hoping to get a few tips and do's and donts. I would like to know who can test and clean the injectors, what rebuild kits are good, and really anything a motor head of my background may need to know about this mean ol' 3.0L. I hope i wont be a pest but im hoping to post progress and questions i may have as i go along. Thank you for any input you may care to post.

 

[Faztbullet]

Re: 225 EFI rebuild

Manual...manual...manual...
Well first determine what caused ring to stick as they dont stick from being "worn out". Measure the cylinders to see if they need boring, the stock I.D is 3.6265 and if .003 out of round it needs boring. Also mike piston to check wear 1 inch above skirt at right angle of wrist pin and it should be 3.6210 if under replace them. If it needs boring use the smallest overbore piston as on EFI there is no way to increase fuel mixture. You can send the injectors and ECU to Brucatosvs.com and have them flowed/balanced and tested.

 

[8upfisherman]

Re: 225 EFI rebuild

What manual would you suggest? I have found a few on line but none i feel i can put full trust in.

 

[Faztbullet]

Re: 225 EFI rebuild

Here is link to purchase and download factory manual.....

http://www.tradebit.com/filedetail.php/9062395-mercury-mariner-service-manual-200-225-efi

 

[8upfisherman]

Re: 225 EFI rebuild

Great..thanks

 

[8upfisherman]

Re: 225 EFI rebuild

Anyone ever use the rebuild kits from Tri-state marine sold on ebay? apparently they manufacture the parts. I bought the above manual and its awesome. Im trying to get an idea on price of the rebuild so im doing some price shopping. Any suggestions appreciated. I also have an opportunity to buy a used powerhead thats in nice shape. Still weighing my options

 

[8upfisherman]

Re: 225 EFI rebuild

and..correct me if im wrong. I assume if i bore block, put all new bearings and pistons, and send injectors and ecu's to brucatos i shouldnt have anything else that would still exist that would cause major failure? I understand i will need to inspect oiling system and perform all the checks on coils and spark and things also. A local shop is convinced a piece of carbon got into a ring and caused the failure. The damage to cylinder is very minimal so i didnt have a super major malfunction. The entire engine only had 70 psi compression except for the bad jug and it was 50. I only have about a billion and a half hours at WOT..actually i dont know for sure how many but it has had a wild 12 years. This however it the first problem i have had with it...anyway im rambling

 

[Faztbullet]

Re: 225 EFI rebuild

They dont make the kits, it the WSM kit less the main bearings. I sell the same kit either way but I also include a new lower end cap as Merc had update. The 3.0 changed from single to double seals and that adds $110 to kit price. If it will clean up at .010 or .020 thats they way to go and dont buy anything till you have block machined and inspected. Reeplace the fuel pump and fuel rail filters also....

 

[8upfisherman]

Re: 225 EFI rebuild

i assumed boring jugs minimal would be best due to the difficulty delivering more fuel and oil to engine. and you already answered my next question about the lower end cap plate. However, i have a few more steps before having engine apart and already i see things that make me question. First of all one of the rod caps seem as if it were copper plated. Im familiar with copper plating in the huge recip semi hermetic a/c compressors i rebuild but i cant see how thats possible inside a boat engine. second, i think i may have lost the injector on #6. The rod is a few.000 loose compared to the others and the bearings i can see thru oil slots are pitted. It looks as if a new crank and rod/rods are a possibility. Ill post again tomorrow after i oper her up.

 

[Faztbullet]

Re: 225 EFI rebuild

If #6 shows pitting it is likely the cranks is pitted to. This is usually due to worn seal on end cap and ingestion of water. Also use the HP powerhead gskt as its better and doesnt hammerout.

 

[8upfisherman]

Re: 225 EFI rebuild

I pulled her apart today. The rod on 6 is bad. The crank shows some discoloration but is not pitted or grooved. All the journals on the crank look smooth and shiny. I think i dodged a bullet on the crank. it sure looks as if the thing leaned out on that jug. I numbered the injectors so i will know if brucato finds a bad one. the screen in 6 wasnt clogged and i didnt look at the others yet. can i buy a good used rod off ebay or mabe a local shop or do i need to buy a new one?

 

[8upfisherman]

Re: 225 EFI rebuild

REEDS...should i do boyesen or mercury racing carbon fiber? i heard that boyesen don last long and that mercury racing reeds perform better.

 

[Faztbullet]

Re: 225 EFI rebuild

Use Chris Carson as his is better than both...
Chriscarsonmarine.com

 

[carholme]

Re: 225 EFI rebuild

8upfisherman:

Sent you a PM.

Gerry

 

[8upfisherman]

Re: 225 EFI rebuild

ok, so im thinking i would like some mild performance mods. I have a full machine shop (minus blind boring machine) at my disposal. I hear tell that milling intake dividers helps and there is a programmer that wires between intake air temp sensor and ecu that is adjustable and gives around 15-20hp gain. I dont want to over do anything or make mods that affect engine life. My Tr-21 is rated at 245 hp so any light mods would be safe and legal. Again, im not so un happy with stock or slightly more. How bout milling heads? Can i use a used rod in place of my worn one or does it have to be new? what do the crank journals measure? im hoping to check them monday

 

[8upfisherman]

Re: 225 EFI rebuild

Thank you for all the help here. I dropped the block off to be bored. The mechanic is a real nice guy i have known for a few years. In the process of telling each other fishing stories he made me an offer to finish my rebuild. The offer was so good that i bagged up the leftover parts and let a professional finish the job. Ill let you guys know how it runs. I bored it .010 or .015 and put carson reeds in it. other than that its stock with a complete going through.