shot a rusted spark plug out of the head

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alk

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so I finally got the boat into the water last week, was running perfect until all of the sudden sounded like rapid gun fire. Shut the boat down, and saw the remains of a spark plug attached to a free plug wire. I didn't have a chance yet to look at what was left behind in the head, but curious what I'm up against here.

I've known since I acquired this boat a couple of years ago that I had an issue; the exhaust manifold gasket was bad, and for some time must have been leaking seawater onto the head. Removing the rusted plugs wasn't much of an option; not only was it going to be impossible to get a socket on them, it wasn't even possible to see where the plugs ended, and the head began. To many other projects though, so I kept putting this one off.

I figure next winter I need to at least replace the head on the inboard side, if not more. But I'm curious if I have any short term options to get a few more hours out of this motor? Drill the hole out bigger, and put a heli-coil in? Does that ever work? Any suggestions how to get the rest of the plug out, ez-out? The plug remains I found in the bilge had no threads, so I assume that is still in the head.
 
Need more info about how the plug came out of the head. Just the ceramic or central section or the part that is threaded.

Do not drill out. filings can do damage to everything in the head and cylinder. Need more info before you continue which gives you more options on how to proceed.
 
Not sure by what you mean by a few more hours. You could remove the intake push rod and rocker for that cylinder and tighten down a little on the exhaust rocker. Then seal the spark plug hole. It should run a few hours that way. Not the way I would do it unless it was an emergency repair to limp home.
 
I ran it the rest of the way into it's semi permanent summer location on one motor - so in theory it could sit in the slip for a few months, and we could do our boating on the other boat. But it would be nice take the boat over to a nearby anchorage on both motors, and over to the travel lift in september at a minimum.

below are two pics of the plug remains. I won't be able to get any pictures of the head until next weekend, and will probably have to pull the exhaust manifold off to really see what is going on.

IMG_20130617_204908_769.jpg


IMG_20130617_204754_094.jpg
 
Should be able to get the remaining piece out with the right size ez out. Start spraying it with some kroil now if you can find some. It will come out.
 
Yes, apply kroil (sp?) or whatever your penetrating oil poison is. Apply it to all of the plugs. If you're lucky, you will be able to get this out. Then replace them all, replace the manifold gasket, and use anti-seize on the new plug threads being carefull not to get any on the electrode. Then cross your fingers and hope for no engine damage.
 
thanks everyone. once I get a picture of the head, I think the optimism of these plugs coming out will drop considerably. While the leaking manifold gasket was fixed a while back, the damage was done. I suppose it's possible I'll be able to get the broken one out via an extractor, the rest on this side of the motor aren't coming out with a spark plug wrench - there's not even enough space to get the smallest of feeler gauges, let alone a wrench, in between the head and the plug - it looks more like the plug melted into a pool of rust with the head - with the white porcelain tip protruding from the mess. hopefully the picture of the head will explain what I'm trying to describe.

If I put an extractor into the remaining piece of broken plug, and it shatters when I try to back it out- I imagine the head has to be pulled and cylinder cleaned out? Should I just remove the head first?
 
You have nothing to lose by trying. If you break the ez out, take the head off. If you get the other half out then your good. If you spray it really good and let it sit a few days it will come out. If it doesn't you can always carefully heat the head a little with a torch. I have taken quite a few out this way. If you pull the manifold off it will make things much easier.
 
I would be seriously considering pulling the engine. It would be much easier to pull the heads (and you will be lucky if that is all that's required). I would consider it a miracle if the ground electrode is still attached. The damage to that spark plug is amazing. Best of luck!
 
I'd try removal. Pull the exhaust manifold. Soak area with penetrant. Position the piston bottom dead, start of compression stroke. Then fill the cylinder with Shaving Cream. I like the "fluted" extractors better than the "spiral" ones. Lord Willing the piece will come out, electrode attached. Then bring the piston up in compression stroke. Shaving Cream will carry most of the debris out.
 
That shaving cream idea is very clever.

Unfortunately with several plugh rusty I suspect the hed will have to come off. Not really a big job if the access is easy. Muriatic does an amazing job on rust but I don't see how it can be used here.
 
+1 on Kroil. I didn't learn about until a few years ago from a machinist. The stuff is big guns! Don't waste you time or money on WD-40 or the like.
 
quote:
Originally posted by OLD HOUSEBOATER

Reality Check. The head has to come off!

Click to expand...


More of a reality check. The engine has to come out. "leaking sea water into the head". Where did all the shavings/rust particles/debris go?

Looking at the plug tells me that the cylinder has had water in it for a long time. Imagine what it must look like on the inside.

Bob
 
Bob:

You are probably correct but isn't it possible that the leak was only external?? Removing the manifold and the head will show if you are correct. Unfortunately there is no way to do a compression check first unless the plugs can come out.

With the manifold off the kroil is worth a try.
 
quote:
Originally posted by pdecat

Bob:

You are probably correct but isn't it possible that the leak was only external?? Removing the manifold and the head will show if you are correct. Unfortunately there is no way to do a compression check first unless the plugs can come out.

With the manifold off the kroil is worth a try.

Click to expand...


Yeah, possible I suppose. At any rate, if the margin around the engine is a small as indicated he'll probably have to remove the heads to get the engine out anyway. So, pull the manifolds and heads first and see what's there. If he can get the plug out and get a bore scope in that'll give a pretty good indication as well.

Either way, it'll be interesting to see inside.

Bob
 
Plug was burning clean, nice and white with nothing on the center electrode. Ill bet the water was leaking externally only. Theres probably nothing wrong with that cylinder. If there was water in the cylinder the plug wouldn't look like that. Kroil it, get that piece out and put new plugs in it. You'll be fine.
 
the rest on this side of the motor aren't coming out with a spark plug wrench - there's not even enough space to get the smallest of feeler gauges, let alone a wrench,
So alk what you are saying here is the remaining three plugs look like the one in your picture? If this is the case you are better off pulling the heads that plug looks like to me that there has been some contamination leakage going into that cylinder.
 
There's actually very good access to the motor, it's an inboard and the deck opens right up above it - just need to pull the exhaust manifold off to get better access to the head. Water wasn't leaking into the head, it was leaking onto the head, and that was fixed when I picked up the boat in 2009. Motor ran fine up to full rpm until right the rusted plug blew out, so if there is any damage, it is from the couple seconds after the plug blew until i shut the motor off - from broken off parts dropping into the chamber, but I'm not very concerned about any water intrusion into the cylinder. The rust you are looking at is from above the threaded section - external to the motor. The head may be coming off this weekend, but the motor won't be coming out of the boat any time soon.

I know I had a can of kroil in the garage, today I only seem to be able to locate the PB blaster. I wish I remembered where i bought the stuff, but I've had it for like 15 years.
 
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