merc 1998 200 hp efi rebuild? resleeve

DIY Eddy

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Joined
Jul 25, 2015
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3
Hi Everyone I just picked up a 98 200 efi 2.5 liter for very cheap $300 it has sat outside for 10 years or more?The previous owner stopped using it because the boat was rotted and parked it a a friends farm, he said it ran fine then.The motor now has a few issues ie.His buddy started the engine a few years back to try and sell it for him and didn't hook up the water hose???it's in the field,and he said it ran great stopped it after less than 1 min.When .I removed the spark plugs to do a complete check on the engine I could see the top starboard piston melted to the head with a hole in it.I have torn down the motor to rebuild it and the piston has disconnected from the connecting arm and the cylinder sleeve is severely damaged from the connecting rod,I mean worn right through to the aluminum block in spots,So this motor ran for quite a while with the piston detached without coming through the block?? I don't know how that is possible?Anyway I don't think all that damage was caused by wingnut running it with no cooling for a bit.All the rest of the cylinders are perfect, no use at all,this engine has not been used much.Even the crank shaft end bearings of the damaged connecting arm are good,It will be very easy to remove the old cylinder sleeve,Can I replace it myself by freezing the new one,maybe in dry ice,And if so where would I get a new sleeve? Thanks in advance to anyone who knows.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,938
Sleeves are not a DIY project as you have to mill top of sleeve off, and you get 1 chance to align ports.It will need to be tested to see if it has cracked thru into water jacket or other cylinder thru bottom of cylinder. This is just the fix as you will need to find what caused cylinder to fail be it a injector,ignition problem or ECU gone bad
 
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DIY Eddy

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Joined
Jul 25, 2015
Messages
3
Thanks fastbullet I was wondering about the top of the sleeve and how it would match in relation to the exhaust port and the height of the deck.I have already have the old sleeve out and the walls look good,only two wear marks in the aluminum at the bottom of the bore no damage above the exhaust port or to the water jacket ,I guess I should have a shop fill it with weld and resleeve? I believe that cylinder seized from overheating,The cooling system was in a mess,the thermostats,water passages in the head,water pump, all partly blocked with sand and silty clay,But also there is a lot of evidence of pre ignition with a hole in the piston and the top melted down to the ring landing. I will check the injectors before assembly and verify the timing once I get it together and running. Thanks once again. P.S If that cylinder was running hot,{Top starboard} would that cause severe pre ignition?
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,938
Cooling problem would show on nearly all cylinders not just a single one. Have a machine shop weld and cut the bottom flush and install sleeve, send injectors and ECU to Brucato and have them flow tested and cleaned and ECU tested out. Remove the idle stabilizer/advance module as these will take out 1 & 3 if bad.
 

DIY Eddy

Recruit
Joined
Jul 25, 2015
Messages
3
Thank you once again Faztbullet I will have the ECU and injectors checked,Do I just unplug the idle advance mod?Is there any other junk I should get rid of like the oil pump, the gears and all look good but are they reliable enough?
 
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