Smoke from engine, one badly fouled spark plug, and water leaking from all all plugs

[Imjus4u2nv]

Hi all,
I want to thank you in advance for reading this- this is a great community.
I have a 1986, MERCURY - ( 90 H.P. (1986 )) Serial No: 0A968445 Model No: 1090726
I was driving home the other day when the engine made started smoking so I cut the engine right away. Even after being turned off she still smoked for another minute or so. I opened up the enngine cover and all the wiring was very hot. I had a problem in the past with one my stator wires, and i am uncertain if this is related but the other stator wire (I replaced one) had no insulation on it and was apparently touching the engine case (grounding).
Got towed in, was able to restart but shut down while i pulled anchor and was gonna limp in but then couldn't ztart back up (I have been having sporadic issues with thh starter and I am still troubleshooting but will save that for another time).
I get back to the dock, solder a new stator wire extension on (two new wires now so thats done), check all the plugs and find one very badly fouled spark plug, but all the other plugs look fine. (see picture)- very hard gray deposits, plugs are almost brand new (installed a month or so ago). I swap out hte plug and get the boat running, let her idle at low rpms for about half hour with no overheating or smoke, no fouling on spark new plug, but have/will not take it out for a full test run until i know more (to avoid additional damage). It may smoke/foul plug when I drive it at higher rpms.
Now the engine is leaking water around all (at least 5 of the 6) spark plugs, which from this site I know is the gasket for the water jacket cover.
I was hoping someone could guide me through the install for the water jacket cover, mainly finding the right gasket. I believe i need part #22 here- http://www.crowleymarine.com/mercury-outboard/parts/278_15.cfm Also any main tips (besides don't break the bolts)- is this an easy fix, will i see the bolts i need to remove?
Also does anyone know why all the spark plugs would be leaking (they were not leaking prior to this (or at least a week ago). I am assuming the engine overheated and blew the entire gasket?
Is it possible the shorting wire somehow messed with the ignition in that cylinder (the wire to the 3rd cylinder looks like it got the hottest and I will replace) and that is what fouled the spark plug. IN other words if I fix the gasket do you think i am good to go?

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Gee, I have never seen a spark plug look like that. it sounds like you overheated that motor badly. You might check compression and see what she has got left.

 

[Faztbullet]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

very hard gray deposits,

That is not a deposit ..it is aluminum throw off from piston eyebrow(deflector). This usually happens to #1 after a major overheat which will allow water jacket gasket to fail also. Usually when you see this that cylinder will be lower on compression and the other will soon follow as they are highly likely to be scuffed and damaged. Timing problems can also cause this but not cause water jacket to fail.Sometimes when this happens it will cover spark plug hole and leave a imprint of plug and you cannnot see piston.

IN other words if I fix the gasket do you think i am good to go?

No as motor need internal attention...

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

When I take the spark plug out I can see into the chamber, the piston has no give, and flywheel rotates fine- in other words she is still running and sounds good but I guess that does not mean it is all good on the inside, and the other spark plugs are perfectly clean.
I will check compression and post the results (I just compression check so I have a good baseline).
Should I wait to install the water jacket gasket- I will prob need a mechanic to come in and check the cylinders and wasn't sure if they have to takes that plate off anyway.
THanks for all the help, much appreciated.

Jared

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Jared, You can pop off the transfer covers and inspect the cylinders and side and top of the piston.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Jared, You can pop off the transfer covers and inspect the cylinders and side and top of the piston.

Thanks Chris- is the transfer cover the same as the water jacket cover? I have the entire engine assesable (as I took off all the supporting frames etc to get to the water jacket cover), and the water jacket cover looks like there is about 12-16 bolts (all one the left and right side of the spark plugs, I used some wd-40 and was able to get them all to budge easily, just waiting for the parts before I take it all the way apart.

I am assuming the transfer cover is under the water jacket cover? Any further help is greatly appreciated.

In the picture below, it looks from the part list that the transfer port is #30 in the diagram. I am assuming this will be on the port side if this is the case (and not under the water jacket). Is there a port for each cylinder as it looks small from the picture.
Jared

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

#30 in the diagram is a the small black box on the top center of the page (couldnt' get it load in greater detail so here is teh link the site.)- http://www.mercruiserparts.com/Show...0&bdesc=END+CAPS,+MANIFOLD+AND+EXHAUST+COVERS

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Jared, The transfer covers are on the starboard side of the motor, opposite of the exhaust cover. There are three individual covers.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Jared, The transfer covers are on the starboard side of the motor, opposite of the exhaust cover. There are three individual covers.

I will be down to the boat tomorrow/Wednesday and will take a look and some pictures and report back with compression numbers also. My starboard side of the engine is covered with electronics (all the control/switch boxes- here are some pictures of the starboard side of the engine. will take pcitures of port side also wheni get down there - if you happen to see the transfer covers can you let me know. THanks so much again, can't thank you enough.

Jared

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Sure, Picture 5 at the very bottom. Looks like one is partially uncovered.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

UPDATE- replaced the water jacket gasket (two busted bolts, what a headache) and it is no longer leaking. I checked spark and no spark to that third cylinder (the one that overheated). I spoke to my brother mechanic and he said you can run it on 5 of the 6 cylinders. Any input on this? I took it out for a quick spin and she ran mint on 5.
I checked compression, not sure if I did it right. When I did in the past the engine was not primed so it would not turn over during the compression check- and got around 125/130 on all 6 cylinders.
Not sure if engine should start to check compression or if you don't want it to start.
When I checked compression after the 3rd cylinder problem, it kept starting as I was checking and as a result got higher compression- all around 145/150 except number 3 which was at 130 (but no ignition in that cylinder).
I am waiting on more help before using the boat as to minimize and other damage, but someone receommended swapping an ingition coil (the likely culprate) from another cylinder but was not sure if this was wise.
Appreciate all the help so far, gonna look to see if I can get to the transfer covers but looks like I have to remove all the eltrical (the switch boxes, coils etc) and I dont think I want to go that far (may never get back running again).

THANKS AGAIN Chris and everyone else who has given there input- you guys are the best!

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Well if you have compression on #3 it is a miracle. Go on the cdielectronics website and troubleshoot your ign system. It could be something as simple as a broken coil, coil wire or corrosion on the wiring. Maybe even a bad spark plug wire. Fix it and run it. Running on 5 cylinders is not nearly as good, as it is les than 5/6 power, and can cause more damage.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

I am afraid with how the spark plug looked that something is messed up in that cylinder (even if not that bad) and afraid if I spark that cylinder back up it could total the engine (if a head etc goes not worth investing the $ to fix).
I am gonna check compression the correct way (the way I did it last time was with it cold and all spark plugs out and will compare numbers again).

Thanks again!

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Pull the bloody transfer cover and have a look at the #3 cylinder.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Pull the bloody transfer cover and have a look at the #3 cylinder.

Thanks Chris- I will, next time I am down (not for a week or two because really busy with work)
I will try to see how I get to the transfer covers and if I need to pull all the electrical off to get to it. When I do I will post some pictures because once inside I won't know what I am looking at.
Are there gaskets for the transfer covers that I should replace after I remove them that way I can order parts in the mean time.
When you said bottom of picture five, did you mean bottom of engine (left side of the picture), or bottom of picture? I am guessing left side of the picture where you can see some bolts.
Thanks for sticking this out with me Chris!

 

[Chris1956]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

You should replace gasket after removing transfer cover. Sometimes the gasket will survive. It will be easy to see if the piston is all scratched up, the cylinder walls are scratched up, and especially if the top of the piston has lost some aluminum.

The top left of picture 5 is the very bottom of one of the transfer covers. You should be able to unbolt the switchboxes and coils, from the block, to get to the middle transfer cover.

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Thats the info I needed- I am confident I can tackle this now. I will order the gasket this week, and will try to take some pics of the job, and will def take pics of the inside.

THANKS AGAIN!

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Check out this video's here- still running on five and running good (for now).
http://forums.iboats.com/mercury-ma...nside-view-high-10x-magnification-629780.html

 

[Imjus4u2nv]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

Some cool videos of the inside of the cylinder and of piston overheated:
http://forums.iboats.com/mercury-ma...nside-view-high-10x-magnification-629780.html

 

[MH Hawker]

Re: Smoke from engine, one badly fouled spark plug, and water leaking from all all pl

That is not a deposit ..it is aluminum throw off from piston eyebrow(deflector). This usually happens to #1 after a major overheat which will allow water jacket gasket to fail also. Usually when you see this that cylinder will be lower on compression and the other will soon follow as they are highly likely to be scuffed and damaged. Timing problems can also cause this but not cause water jacket to fail.Sometimes when this happens it will cover spark plug hole and leave a imprint of plug and you cannnot see piston.

No as motor need internal attention...

+1 You have a serious issue