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Boat spark plug blew up!
Topic Started: Apr 26 2012, 10:09 PM (3,038 Views)
snowfish
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Basic GearHead

Might want to check out I-boats. :hmm I briefly did a search, about spark plug problems, and found these topics. :news

http://forums.iboats.com/search.php?searchid=2975905

Be sure to subscribe to your topics. Site gets a ton of activity. ^o)
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Spock
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Live Long and Prosper.

geojojo
Apr 26 2012, 11:04 PM
Spock
Apr 26 2012, 10:48 PM
Yep, the head pretty much has to come off. I work on Honda outboards for a living and I have seen this kind of thing before. Although, the last time I took a set of heads to a machine shop the guy told me that he could have repaired the threads with the head still on the motor. I guess it can be done, just not the preferred method in my opinion.

Of course, once you start putting a wrench to bolts that have been in/around salt water you may be opening a can of worms. :die

Good luck :thumb
I think the head has to come off anyway, some metal shavings most likely fell into the cylinder hole when we broke the hex off, and as for the rusted bolts, we have special sockets designed for rusted bolts, they spiral in and get tighter as you turn the wrench, but I hope those bolts don't give me too much trouble.
Its not so much rounding the heads off the bolts that you have to worry about, its snapping the bolt off altogether. That's when the fun starts! :die :die :banghead :banghead :banghead

Seriously, dropping a few shavings into the combustion chamber is not ideal, but it's not necessarily the end of the world either. I can tell you a few stories about foreign objects going into the combustion chamber and blowing out the exhaust with very little issue. For instance, I had a brass jet work itself out of one of my carbs on my 2-smoke Mercury Black Max and got sucked all the way to the combustion chamber. It ruined the spark plug before it ejected itself out the exhaust port. I was convinced there was major damage so I pulled the head. Everything was totally fine other than the spark plug.

I have a few other stories like that from personal experience. My point is that engines are pretty tough, and I don't think a few shavings from the drilling and insertion of a helicoil would likely cause you problems. It's not the best idea by any means, but for the most part I think you can get away with it.

It's a risk VS rewards kinda thing. What kind of 'can-o-worms' are you are you going to open when you start to pull that head off? Is it going to need to be machined for straightness? Are a dozen bolts going to snap off requiring you to spend a ton of money at the machine shop to get them repaired? The list goes on and on.

In the end, pulling the head and doing it right is the right thing to do but you should be prepared for complications. Perhaps you should call a machine shop and see what they have to say before you go diving in head first.

Good Luck!
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Coche Blanco
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Troll Certified

If I did that, I would at least get a nozzle down in the cylinder and try to blow all of them out with compressed air.
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me2


Coche Blanco
Apr 28 2012, 08:26 AM
If I did that, I would at least get a nozzle down in the cylinder and try to blow all of them out with compressed air.
Or make a 'tip' for a shop vac and then let the starter spin the motor.
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Coche Blanco
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Anything really, I wouldn't knowingly let metal shavings bounce around in my engine.
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me2


Coche Blanco
Apr 28 2012, 09:29 AM
Anything really, I wouldn't knowingly let metal shavings bounce around in my engine.
Hey, do both huh? I agree. Try the blow job first and then some add some suction if it seems necessary.
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geojojo
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The spark plug problem was fixed, the next time we took it out, it started to have a bad knock so we changed out the lifters, but the bad lifter turned out to be the one for the exhaust valve in cylinder #2 which caused a spun bearing in that same cylinder, so out came the engine, I plan to get a new set of bearings then use plastigage to check that it clears specs (hopefully it does) then ill be back out on the water this year to come :)
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HelterSkelter
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#1 Pizza Driver

hit it with some kroil/pb blaster, whack it a few times, hit it with a blowtorch if you have one (being careful not to heat anything up too much, just enough to get it kinda hot), and then stick a bolt extractor down into it and it will come right out.
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geojojo
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Got the engine on an engine stand in the garage (upside-down by the way)
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Deleted User
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Put anti-seize compound on the spark plugs. Use a torque wrench and tighten to spec.

If you're not going to operate the engine for a while, remove the spark plugs, and install some dehydrator plugs.

http://www.theultralightplace.com/dehydrator_plugs.htm

If there's any corrosion at all on the spark plugs when you remove them, toss them in the recycle bin, and get some new ones to put in next time.

The good news is, there's no monetary reason that that broken spark plug will not come out! :thumb
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Coche Blanco
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Geo Glenn
Nov 20 2012, 08:33 PM
Put anti-seize compound on the spark plugs. Use a torque wrench and tighten to spec.

If you're not going to operate the engine for a while, remove the spark plugs, and install some dehydrator plugs.

http://www.theultralightplace.com/dehydrator_plugs.htm

If there's any corrosion at all on the spark plugs when you remove them, toss them in the recycle bin, and get some new ones to put in next time.

The good news is, there's no monetary reason that that broken spark plug will not come out! :thumb
Dehydrating spark plugs....learn something new everyday.
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Spock
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Live Long and Prosper.

Coche Blanco
Nov 20 2012, 08:43 PM
Geo Glenn
Nov 20 2012, 08:33 PM
Put anti-seize compound on the spark plugs. Use a torque wrench and tighten to spec.

If you're not going to operate the engine for a while, remove the spark plugs, and install some dehydrator plugs.

http://www.theultralightplace.com/dehydrator_plugs.htm

If there's any corrosion at all on the spark plugs when you remove them, toss them in the recycle bin, and get some new ones to put in next time.

The good news is, there's no monetary reason that that broken spark plug will not come out! :thumb
Dehydrating spark plugs....learn something new everyday.
Seems like a colossal waste of money to me, on a gimmick that may or may not work. A tablespoon of oil down the spark plug hole and spin the engine around a few times will serve the same purpose at a tenth of the cost and double the simplicity.
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Deleted User
Deleted User

AN4062-1 dehydrator plugs have been used in the aircraft industry as a gimmick for years, just to get aircraft owners to spend way more money than is absolutely necessary . . . It all started with the Government dreaming up ways to waste taxpayer revenue . . . :O :'(

Every new TCM IO-550-BB for the Bonanza and Baron that rolled into the aircraft manufacturer formally known as "Beech Aircraft" had 2 of these little jewels installed in each cylinder.

No reason for boaters to have it any easier . . . :news

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Woodie
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geojojo
Nov 19 2012, 09:33 PM

Posted Image
The answer to why you're having so much trouble with this engine is highlighted in orange in the picture above.
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billy508
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billy508

Spock
Apr 28 2012, 08:20 AM
geojojo
Apr 26 2012, 11:04 PM
Spock
Apr 26 2012, 10:48 PM
Yep, the head pretty much has to come off. I work on Honda outboards for a living and I have seen this kind of thing before. Although, the last time I took a set of heads to a machine shop the guy told me that he could have repaired the threads with the head still on the motor. I guess it can be done, just not the preferred method in my opinion.

Of course, once you start putting a wrench to bolts that have been in/around salt water you may be opening a can of worms. :die

Good luck :thumb
I think the head has to come off anyway, some metal shavings most likely fell into the cylinder hole when we broke the hex off, and as for the rusted bolts, we have special sockets designed for rusted bolts, they spiral in and get tighter as you turn the wrench, but I hope those bolts don't give me too much trouble.
Its not so much rounding the heads off the bolts that you have to worry about, its snapping the bolt off altogether. That's when the fun starts! :die :die :banghead :banghead :banghead

Seriously, dropping a few shavings into the combustion chamber is not ideal, but it's not necessarily the end of the world either. I can tell you a few stories about foreign objects going into the combustion chamber and blowing out the exhaust with very little issue. For instance, I had a brass jet work itself out of one of my carbs on my 2-smoke Mercury Black Max and got sucked all the way to the combustion chamber. It ruined the spark plug before it ejected itself out the exhaust port. I was convinced there was major damage so I pulled the head. Everything was totally fine other than the spark plug.

I have a few other stories like that from personal experience. My point is that engines are pretty tough, and I don't think a few shavings from the drilling and insertion of a helicoil would likely cause you problems. It's not the best idea by any means, but for the most part I think you can get away with it.

It's a risk VS rewards kinda thing. What kind of 'can-o-worms' are you are you going to open when you start to pull that head off? Is it going to need to be machined for straightness? Are a dozen bolts going to snap off requiring you to spend a ton of money at the machine shop to get them repaired? The list goes on and on.

In the end, pulling the head and doing it right is the right thing to do but you should be prepared for complications. Perhaps you should call a machine shop and see what they have to say before you go diving in head first.

Good Luck!
Of course, once you start putting a wrench to bolts that have been in/around salt water you may be opening a can of worms.

One of the best posts ever on marine stuff. If you dont believe it , then you just have not worked on enought marine equipment. thanks for a heads up post.
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