1998 Mercury 200 EFI Mechanical Damage Rebuild

[Bigwrench]

Just got off the phone with the Local Machine Shop that does all the Marine Service Department work in the area and they Charge $45 a hole, they wont be able to even get to it until the first of next week. That will give me time to get my parts ordered and also I can send a piston over with the block so they can match it to that piston. Mercury is running .007" difference between piston and cylinder wall so as long as they have a piston to go by they can match it up perfectly. Actually thought about cutting them all .020' over, with a new set of CF reeds that should give me about 225 hp to the prop (just kidding ,have no idea really but sounds good) LOL

OK as to the fuel system , I have been going on the premise that this was a head gasket failure based on this photo




I honestly cant 100% with certainty what the failure was and Id sure hate to put it all back together and find out I still have an issue at #6. Would be my dang luck though LOL
To me this picture above is a classic head gasket failure , on an 18 year old gasket..... it made sense when I saw it. Now to be honest Im not happy and I didn't get that warm and fuzzy feeling from my repair shop experience at the dealer recently, since I work at a dealership and kinda know the ins and outs of the experience from both ends, it was probably a big waste of money/time taking it there. One head was removed and Lower unit dropped & the charge was $156 (1.5 hrs) but couldn't tell me any sort of opinion as to why it happened ...... if I did that to a customer lol Id be looking for a new job. BTW I watched a guy drop a lower unit on one of these 200's last night on a YouTube video in .....6 mins lol . Not trying to knock the dealer but facts is facts lol But live and learn right ?
Anyways regardless it has to be built and I appreciate all the input, while its off it sure wont hurt to clean and flow the injectors , Ill have to do some research on them and see what voltage they are driven at but have several different injector tests that I can run as long as they are driven at 12VDC or less . I guess I am worried if it is an ECM or injector issue its gonna throw me into the replacement category and if so at this point I should just drop the cash for a 200ProXS with 5 years wty and be done with it ? Just some thoughts I been pondering

[Oldfart9999]

I would think there are specs you can check against, this way you can make a decision before you send it for work you won't need because you're going to replace it. That doesn't seem to be a bad price for fitting a piston.
Rodney

[Bigwrench]

I would think there are specs you can check against, this way you can make a decision before you send it for work you won't need because you're going to replace it. That doesn't seem to be a bad price for fitting a piston.
Rodney

That does seem reasonable for sure , I can repair the powerhead assembly and research the fuel and ECU systems more in the process.

[merc1997]

Just got off the phone with the Local Machine Shop that does all the Marine Service Department work in the area and they Charge $45 a hole, they wont be able to even get to it until the first of next week. That will give me time to get my parts ordered and also I can send a piston over with the block so they can match it to that piston. Mercury is running .007" difference between piston and cylinder wall so as long as they have a piston to go by they can match it up perfectly. Actually thought about cutting them all .020' over, with a new set of CF reeds that should give me about 225 hp to the prop (just kidding ,have no idea really but sounds good) LOL

OK as to the fuel system , I have been going on the premise that this was a head gasket failure based on this photo




I honestly cant 100% with certainty what the failure was and Id sure hate to put it all back together and find out I still have an issue at #6. Would be my dang luck though LOL
To me this picture above is a classic head gasket failure , on an 18 year old gasket..... it made sense when I saw it. Now to be honest Im not happy and I didn't get that warm and fuzzy feeling from my repair shop experience at the dealer recently, since I work at a dealership and kinda know the ins and outs of the experience from both ends, it was probably a big waste of money/time taking it there. One head was removed and Lower unit dropped & the charge was $156 (1.5 hrs) but couldn't tell me any sort of opinion as to why it happened ...... if I did that to a customer lol Id be looking for a new job. BTW I watched a guy drop a lower unit on one of these 200's last night on a YouTube video in .....6 mins lol . Not trying to knock the dealer but facts is facts lol But live and learn right ?
Anyways regardless it has to be built and I appreciate all the input, while its off it sure wont hurt to clean and flow the injectors , Ill have to do some research on them and see what voltage they are driven at but have several different injector tests that I can run as long as they are driven at 12VDC or less . I guess I am worried if it is an ECM or injector issue its gonna throw me into the replacement category and if so at this point I should just drop the cash for a 200ProXS with 5 years wty and be done with it ? Just some thoughts I been pondering

based on your pic, if #6 was fuel starved and galled and heated up, they the # 6 gasket ring would have been burned from #6 cylinder bore out to # 4.  But, #4 has burned out to # 6.

if #6 gasket ring had burned coupled with how the piston looks, then yes, fuel delivery could be the root of the failure.  chasing down the original cause of failure is definitely a forensic science in itself.  remember me suggesting to check your lower unit?  many power head failures begin in the lower unit.  when something in the lower unit is dragging, it is also stressing the power head.  and, when you have a lock up in the low end, pop goes something in the power head.  as i remember # 4 plug was clean, which is what will happen with water going into the cylinder.  the cylinder with piston damage had a fairly normal looking plug which indicates the presence of adequate fuel.  a cylinder with lean fuel will have a very clean plug.

bo

[Bigwrench]

based on your pic, if #6 was fuel starved and galled and heated up, they the # 6 gasket ring would have been burned from #6 cylinder bore out to # 4.  But, #4 has burned out to # 6.

if #6 gasket ring had burned coupled with how the piston looks, then yes, fuel delivery could be the root of the failure.  chasing down the original cause of failure is definitely a forensic science in itself.  remember me suggesting to check your lower unit?  many power head failures begin in the lower unit.  when something in the lower unit is dragging, it is also stressing the power head.  and, when you have a lock up in the low end, pop goes something in the power head.  as i remember # 4 plug was clean, which is what will happen with water going into the cylinder.  the cylinder with piston damage had a fairly normal looking plug which indicates the presence of adequate fuel.  a cylinder with lean fuel will have a very clean plug.

bo

Doctor Bo on the job !!  As you know I agree with you on that synopsis from our discussion on the phone other day. But excellent way to break it down for everyone. I have trouble putting my thoughts out there and explaining my findings so everyone can understand em , when I'm training a young tech I usually just shove em outta the way and say "do it like that" lol
Glad you are here to share your thoughts , funny story and a little off topic but I have been searching the World Wide Web for anything and everything merc repair relating to my rebuild and there were several instances where good old Google led me to posts you were involved in ..... A looooong time ago lol. Again I really appreciate yours and everyone else input. I don't want to overlook anything that may cause a stupid mistake ($$$$) by just assuming that's how I would do it on a car so it must be right (top cap bearing for instance lol)

[Oldfart9999]

So the problem could have been a bad gasket or head bolts needing re-tightening?
Rodney

[Bigwrench]

So the problem could have been a bad gasket or head bolts needing re-tightening?
Rodney

Yeah it appears so ,Bo said it a lot better than I can but its evident that the problem started on the #4 cylinder. The Sealing ring is completely gone on #4. I haven't measured it yet but I would bet a dollar the head is warped there also 

[Bigwrench]

Just an update to keep everyone on board , the pro rebuild kit was ordered and should be here sometime next week, it includes everything except head bolts, they also said they'd swap out one Port STD piston for a Port  .020" over so I wont have to purchase an additional piston 
  As soon as the kit gets here I am going to send the block and the one oversized piston to the machine shop to punch #6 hole and Ill probably have them hot tank the motor afterwards but not sure (Depends on cost) cause I am gonna scrub the cylinders and block anyways before the rebuild starts. Stay Tuned !

[Oldfart9999]

Do the other 5 jugs need honing?
Rodney

[Bigwrench]

Do the other 5 jugs need honing?
Rodney

No sir , I'm good on those at STD size. Thank goodness.

[Oldfart9999]

Good deal!
Rodney

[Bigwrench]

Most of the Parts arrived today !!!
Still waiting on a Cylinder head , water pump, Crankshaft sealing rings and 2 thermostats

[Lipripper]

Maybe you will get them soon.

[Bigwrench]

Maybe you will get them soon.

I received the notification that they were packed up today and should ship tomorrow.  Now I can at least get the block over to the machine shop and get that cylinder punched .020 !!

[88evinrude]

man that things going to be better than new.

[Bigwrench]

Picked up my block today while I was in Tn for a Dr appt. looks fantastic !


Did have one setback , the last and final order of parts showed up Friday night but instead of getting 7 crankshaft sealing rings I received 7 water diaphragms lol !

  The good stuff

  I'd like to point out that these are all original Mercury parts
  And a FYI the local dealer outed me I think it was $350 for  a head. This one was like $113 and change !



When I called the company they said it was a Mercury catalog error and the original part number superseded to this number so still on hold until the rings get here

[Princeton_Man]

Looks great Rick! Looks like you'll get it back together in time for your May trip to Big G.

[Bigwrench]

Looks great Rick! Looks like you'll get it back together in time for your May trip to Big G.

I hope so ! Even Tammy seems to be getting excited about the trip lately ! We are definitely gonna fish at least one day with Jake so I know she will some fish anyways.

[Princeton_Man]

I hope so ! Even Tammy seems to be getting excited about the trip lately ! We are definitely gonna fish at least one day with Jake so I know she will some fish anyways.

That's awesome! I've thought a few times about going down to fish with him. He can put you on the fish! I'm expecting that once you have it completed and broken in, you're going to find some power in the Merc that you haven't seen before.

[Bigwrench]

Ok so let's get this party started !

  Got some free time after , Soccer game  (Holston_Slayer scored 7 goals ! ) , Golf Cart Maintenance, wash, Wax, Buff and detail.... Ok I'm already tired lol
Here goes !

I want to start with a completely clean block and I wasn't happy with my earlier Hone "witness marks" so I quick cut the witness marks in with the Hone using the same procedure above in the 5 standard cylinders.  Slow speed , WD-40 used very liberally and long deliberate .001" strokes it looks perfect !

That to me is a perfect hone !
Mercury provides very thorough instructions on how to properly hone a cylinder wall here

Once the cylinder walls were where I wanted them it was time to clean this thing up and remove any traces of oil, grit and metal.

Made me a temporary stand out of a spare bucket and poured purple power over the entire block . I like the degreasing capabilities and also the slight acidic reaction it causes to clean the surfaces (especially aluminum)

I started scrubbing the walls with dish soap and water using a NEW toilet scrub brush , otherwise it would have been a "Crappy" job ! I then switched to a hand held sponge and cleaned each cylinder individually , top to bottom. 



Flipped the block over and scrubbed the bottom using the same setup.
Rinsed everything extremely clean with the garden hose making sure to hit all passages and bolt holes.

Flipped back over and rinsed the top as well.

  Once everything was squeaky clean I then used an air wand to blow out every bolt hole and all of the cylinders and water passages. 



  IMO cleanliness is the number one most important factor in ensuring a long lasting and dependable rebuild job.
  It's also very very important to blow any water, oil or debris out of the bolt holes . Believe it or not you can crack a block by tightening a bolt into a hole that has water or oil in it !
Don't ask me how I know this , just trust me it can and will eventually happen if you are careless.

Details , Details !

Once the block is clean liberally coat the cylinder walls (steel) with 2 Stroke oil

you don't want all your hard work to go to waste by surface rust setting in which can happen very quickly on recently honed steel.
Once the cylinder walls are lubed up good , I wrapped the block in an old cotton sheet and set it aside.

Don't Tell MommaWrench I'm using her sheets !
      It's time to build some Pistons !

[Princeton_Man]

That's going to be a motor I'd buy, even if it is a Merc!

[Bigwrench]

That's going to be a motor I'd buy, even if it is a Merc!

Now that's a compliment coming from a die hard Rude man lol

[Bigwrench]

Ok remember that freshly waxed and detailed golf cart ? It has now become my piston building table

The matching sheet also is being utilized
Shhhhhh!


Perfect height for me to sit on my brake stool and work , right under the light.


I'm a stickler for organization when doing a rebuild so everything that's laid out , even the new Pistons get a Sharpie number that will correspond with the original numbers on the Connecting Rods and Rod caps.


You always want everything to go back together in the same location and direction that it came off the original motor.

Piston Disassembly :

To disassemble the original Pistons and rods we will use a small flat bladed pocket screwdriver with a magnet on one end (more on that in a bit) .
On each side of the piston where the piston pin holds the piston and the connecting rod together there is a clip that retains the pin into the piston by sitting inside a small groove , there is also one notch . Insert the flat edge of your screw driver in behind the circlip and gently pry it away from the piston towards the center and lift up . It is very strong and under pressure so use caution , wear eye protection and place your free thumb over it to prevent it from flying out and putting your eye out !


 

Remove both circlips , Discard the clips since we are replacing all Pistons , Pins, bearings and circlips.
  Once both clips are out of the way, we can now remove the piston pin . I like to use a deep well socket that has a slightly smaller outside diameter , in this case I am using a 1/4" drive 13mm socket as a "punch"

These pins can be really stuck good in this instance they aren't too bad so as a "Hammer" I am using a large screwdriver handle to tap the socket through the piston , pushing the pin out the other side.  I have had to use an actual ball peen hammer. I just like to use as much force as necessary.
Remember ......
"Your Mileage May Vary"

Once the socket is past the far side of the connecting rod the 2 washers and all the needle bearings will fall out once you remove the socket. It's hard to hold the phone and snap a picture so the above picture was for reference in how I hold the assembly while tapping.
Ok here's a as you go change up , the 1/4 drive socket wasn't long enough to push the pin through enough to release the connecting rod .

I switched over to a 3/8" drive deep well 1/2" socket for the extra length.

Here's the Mercury procedure outlined for piston pin removal for reference


Here's what everything looks like inside to give you an idea of the assembled view.

New socket in and finish it up


Here's a tip , leave the socket in once the pin is past the connecting rod. It will hold all those small bearings and washers shown here

in place until you can hold the whole thing over someplace (my "table" in this instance) where you won't lose all the small parts.  Should be 2 flat washers and 29 needle bearings.

Remember the connecting rod has to go back on the new piston in the exact same direction it came off the old one
Reference your original Sharpie arrow marks .

In my instance all arrows point toward the top or flywheel of the engine.

Piston assembly will begin tomorrow , it's time to get some vittles in my belly .

[merc1997]

looking very good buddy!

bo

[Bigwrench]

looking very good buddy!

bo

Thanks Bo ! Hope it runs as good as it looks lol