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Cross Threaded SparkPlug

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Rangerman2019

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Last year when winterizing my Verado 250 I started to feel the sparkplug wasn't going in properly so I pulled it out and looks like the first thread to 2 threads were getting cross threaded. Now will using a thread chaser fix this? or is going to a mechanic my best bet?

Thanks
Paul
 
If you have experience doing this type of work then go for it.-----The rule years ago was----" loosen the plug with a wrench and then take it out with fingers, install the new plug with fingers and snug up with the wrench"
 
Hey Racerone,

For some reason I let myself get distracted and messed up, plus with the Verado 250 can't get my fingers all the way into the cylinders, hope the thread chaser works.
 
Rangerman2019 said:
Hey Racerone,

For some reason I let myself get distracted and messed up, plus with the Verado 250 can't get my fingers all the way into the cylinders, hope the thread chaser works.
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Make sure its a chaser, do not use a tap, Cover it with grease, most of what comes loose will stick to the grease.....

Don't screw it up, you cannot just pull the head off. If you feel 5% uncomfortable doing this, take it to a pro.
 
Again I need to make it clear.---------Use finger power to remove plugs and finger power to install them.--------Wrench is used when needed to torque them
 
Hey guys,

Thanks for all the tips, I have a buddy that was an engine man in the Navy and worked as a mechanic and a marina and is certified on Johnson motors, it's one of those 50/50 things could go right or wrong, will have to wait until the weather warms up in Chicago to see how it works.
 
Hi Chris,

I found the 14mm back tap and ordered it, thanks for that tip, with using a thread chaser he was about 60% confident now with this he is 100% confident, again really appreciate the help.
 
Okay, what I use on these to hand start the plugs is a short straight piece of rubber fuel line hose, pushed on the plug. Another good thing to use is an automotive plug boot. This gives you enough guidance to correctly start the threads. NEVER start with a socket and extension. And since we are dealing with "dissimilar metals", always use a little anti seize on threads. I like nickel formula for most applications, but on the big diesels, we use a lot of Molykote too.
 
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Even though the manual suggests anti-seize may be used on the plugs, we never do that unless you have their specified anti-seize.

If you use anti-seize with graphite in it you will have a major problem.

Anti-seize makes it easy to over torque the spark plugs which will also lead to a major problem.

Change/check your plugs every year and you will not have an issue.
 
Right, to each his own. For me, it's anti seize and I do recommend it to others. We rebuild the big engines on vessels of the great lakes, as well as the Navy. I have had to retire early from the " big stuff" but might go back if my upcoming surgery plays out well. The engines we mostly overhaul are 8000/9000 hp Pielstiks. In normal use, they run 4 years between overhauls. There are plenty of delicate parts in these babies. The controls, governor's, injector cooling systems, air start system components. It is so refreshing going back to an engine after 4 years, and things come back apart so beautifully.
 

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timguy said:
Right, to each his own. For me, it's anti seize and I do recommend it to others. We rebuild the big engines on vessels of the great lakes, as well as the Navy. I have had to retire early from the " big stuff" but might go back if my upcoming surgery plays out well. The engines we mostly overhaul are 8000/9000 hp Pielstiks. In normal use, they run 4 years between overhauls. There are plenty of delicate parts in these babies. The controls, governor's, injector cooling systems, air start system components. It is so refreshing going back to an engine after 4 years, and things come back apart so beautifully.
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Your knowledge of large vessel engines does not apply to a Mercury Verado 250HP Four Stroke supercharged outboard.
 
Hey pal, everything we learn in life goes into a big databank. Don't be ridiculous, we are talking about a SPARK PLUG and anti-seize. What you might think doesn't apply because someone might overtorque a bolt or spark plug is rubbish. What I learned from rebuilding a 9000 hp diesel can be applied to a 1 1/2 hp "Mighty Mite". In aviation as well as marine, dissimilar metals need to be addressed and anti-seize has an important place in most assemblies. Why do you want to argue with someone who not only is correct.......but argue with someone who obviously has broader knowledge and is more open minded than you? You're just jealous because I got a bigger piston than you!
 
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timguy said:
Hey pal, everything we learn in life goes into a big databank. Don't be ridiculous, we are talking about a SPARK PLUG and anti-seize. What you might think doesn't apply because someone might overtorque a bolt or spark plug is rubbish. What I learned from rebuilding a 9000 hp diesel can be applied to a 1 1/2 hp "Mighty Mite". In aviation as well as marine, dissimilar metals need to be addressed and anti-seize has an important place in most assemblies. Why do you want to argue with someone who not only is correct.......but argue with someone who obviously has broader knowledge and is more open minded than you? You're just jealous because I got a bigger piston than you!
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First, I am not your "Pal".

Again, your skill set does not apply here. This is not a 9000 HP diesel. If someone asks me about a 9000HP diesel, I will direct them to you.

If you would like to add to your "Data bank" Sit back, read and understand, don't add anything unless you have experience on the engine we are discussing.

Here Expand your "Data Base"

http://www.jagrepair.com/images/AutoRepairPhotos/NGK_TB-0630111antisieze.pdf
 

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Mr. Chris. This is a good information. Okay I'm not your pal. Its clear to see you will do anything you can to prove me wrong. The cold hard fact here is that the mistake in the photos show that the spark plug was "over-torqued", whether it had anti-seize on it our not. The error was the fault of the installer....and not the anti-seize. I detect a portentous attitude on your part, so I will back down. Worked with many men who share your character.
 
timguy said:
Mr. Chris. This is a good information. Okay I'm not your pal. Its clear to see you will do anything you can to prove me wrong. The cold hard fact here is that the mistake in the photos show that the spark plug was "over-torqued", whether it had anti-seize on it our not. The error was the fault of the installer....and not the anti-seize. I detect a portentous attitude on your part, so I will back down. Worked with many men who share your character.
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My final word on this thread unless the OP has questions.


Sorry, no one has my character and I don't care to impress anyone. I deal in facts. My many customers know that. I am also what you would call a forensic diagnostic mechanic.

Don't care to prove you wrong, just don't want people who are here seeking advice to do thing they shouldn't. Read the NGK SB one more time. You missed the most important part.
 
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Okay, fine. If that factory coating is worth a damn, then why were the NGK spark plugs in my 1999 F150 Lariat 4.6 rusted in? Its never been in the salt and always parked in a garage. Got only 50,000 kilometres on it. That factory coating, Chris, is not adequate for many applications. I'm sure you already know that these plugs are deep down in a hole that is protected by a rubber seal on top of the spark plug boot. Anyone with reasonable experience would never break off a spark plug as depicted in the NGK illustration. Go ahead, try it yourself.....I already did.
 
Hi Chris,

Your backtap worked like a charm, the engine guy I know had no issues fixing the cross threaded threads. Thanks again for all your help really appreciate it. Well that issue was logged at the front of the memory back now that's for sure, that won't or at least shouldn't happen again.

Thanks
Paul
 
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