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Discussion Starter #1
My question is about the right rear plug. What a freaking nightmare...I was very slow when trying to sit and rethread the new plug. I couldn't really get it started with a hose attached to the top of the plug but after dropping it down in there a few times I got it started with the deep socket attached to the plug. I spent a good 1/2 hr. turning it from slightly different angles thinking it should thread loosely for most of the way in but after a few threads there was resistance. I finally committed and wrenched the socket until it stopped then gave it another quarter turn. I did not torque it. It started and is running smooth. Would I know if it wasn't seated properly and I cross threaded it? If it wasn't seated properly would there be evidence of this in the way it ran? Paranoid!
 

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There is really no way to know if you cross threaded it even slightly. Usually the plug will spin in until it touches the sealing ring but can have a slight resistance too.
You are probably ok. Did you use any anti sieze on the threads?
 

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Ive had new plugs that went in snug on cars before, to where I could not screw it in with the extension on the socket, I had to put the wrench on it.

I know what you mean, its a sick feeling. As long as it went in with pretty much the same slight torque all the way, like two fingers on the ratchet wrench you are ok. If it was cross threaded I think it would get harder and harder to screw in as it went.

If you did cross thread it, its not the end of the world, you can put a helicoil in if you need to. When you take it out next time check the threads on the plug for stripped out aluminum.
 

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Discussion Starter #5
I'm getting a new front tire next week. I'll have them take a look. If the plug is not all the way in I assume it would run rough. Thanks for the reply.
 

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We are talking steel base of a plug going into aluminum so it is possible you had resistance because there could have been a little crud in the threads when you removed the old one. I once crossthreaded a plug so bad on a dirt bike when I was a kid, it blew the plug out after i started it! Like kcw said, we all been there.
 

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Hope all turns out OK for you. From past experience I will not put a new plug into anything without antiseize. I stipped a plug hole in a very expensive set heads once in a race motor. That was a very bad day.
 

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I wonder if you can get a nut that is the same size as the threads on a spark plug? Then if the plug does not seem to want to screw in right, you could take it out and screw the nut on the spark plug to chase the threads and clean them up. I think the threads are 14mm x 1.25mm.

It has never occurred to me to check the threads on a spark plug before installing it. I guess they could get buggered up a bit if the spark plug was mishandled or dropped somewhere.
 

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one other thing that can happen, if your engine is running rich and there is a lot of carbon on the plugs,

as you take them out the carbon will deform the threads in the aluminum head. When you put the new clean plugs in they will need to push the threads back into shape a bit. So if your plugs were fouled you can expect the new ones will go in a little tight.
 

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Hope all turns out OK for you. From past experience I will not put a new plug into anything without antiseize. I stipped a plug hole in a very expensive set heads once in a race motor. That was a very bad day.
Agreed. I almost broke off the threads in the park plug hole on a dodge truck once because the previous owner did not use any antisieze and the plug was rusted in the head. A tube of antisieze will last almost a lifetime!
I wonder if you can get a nut that is the same size as the threads on a spark plug? Then if the plug does not seem to want to screw in right, you could take it out and screw the nut on the spark plug to chase the threads and clean them up. I think the threads are 14mm x 1.25mm.

It has never occurred to me to check the threads on a spark plug before installing it. I guess they could get buggered up a bit if the spark plug was mishandled or dropped somewhere.
Yep I have seen threads dinged up from the factory and possible it happened to him making it seem he was crossthreading it.
I worked for a company where we used to make hydraulic fittings and one of the workers was just tossing them in the box. Our quality department had to reject about 5000 fittings because all the threads and sealing surfaces were all banged up. We would sample batches using go and no-go gauges.
 

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Discussion Starter #11
I haven't ridden it since I put the plugs in. I'll take them out and apply anti seize. Hate to mess with the troublesome one again but at least I'll know more. Thanks for the input. Especially the one about ruining the race motor. That put my mind at ease. :wink:
 

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Not that it will help now.. but i always when putting in new plugs .. turn a new plug backwards/Reverse until it falls into the thread and than thread in by hand ..than tighten to spec.. less chance of cross threading that way :) But I always use anti seize.. Especially since I know i'm going to be the next one taking them out. :)
 

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I haven't ridden it since I put the plugs in. I'll take them out and apply anti seize. Hate to mess with the troublesome one again but at least I'll know more. Thanks for the input. Especially the one about ruining the race motor. That put my mind at ease. /forums/images/StarbikeForums_2015/smilies/tango_face_wink.png
I wouldn't worry about it since they are in already. Get it next go around!
 

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Count the number of threads that are exposed under the crush washer on your spark plug and that's the approximate number of full turns it would take to install/remove it... that's one way to ensure that it is fully seated on installation.
 

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Discussion Starter #15
From NGK website...
NGK spark plugs feature what is known as trivalent plating. This silver-or-chrome colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without the use of anti-seize. NGK tech support has received a number of tech calls from installers who have over-tightened spark plugs because of the use of anti-seize. Anti-seize compound can act as a lubricant altering torque values up to 20 percent, increasing the risk of spark plug thread breakage.
 

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Manufacturers have there specs for a lot of things and they are meant for pristine conditions.. if you remove a plug than the coating is worn off so you will need to put more something on it. Anti-seize. Is this against the manufacturers recommendations.. NO . They have warnings for the many that will do but not know and make mistakes.. this gives them an out on warranty when needed.

Highwayman do what you want but if you are going to do the maintenance on this bike consider what others say..

Brembo rotors say not to lube between the rotor and hub when installing new rotors.. But I bet they don't have Canadian winters and Salt used on the streets in the UK or southern USA.. Again they have this warning for the guy that puts too much lube/grease on as it can cause the rotor to be offset/warped.. but in good practice a good or in the know mechanic / person will be cautious and not over do it. But they (Brembo) still needs to cover there butt.

On NGK's note.. use the lube and under torque your spark plugs to be on the safe side. I wouldn't but I have been turning wrenches for over 25 years so that's up to you.
 

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Discussion Starter #18 (Edited)
Update...the right rear plug was only screwed in about 4 threads on the plug. It seemed louder than usual but it was running fine. I can't see down in there so I didn't know. Managed to get it out and as you can see the cylinder head threads look stripped. I did get a new plug in (with anti-seize) and surprisingly it threaded properly and I got it torqed to 12.7 lb ft. Hope all is good.
 

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Thats a bit scary that you had the plug cross threaded, but since you have it in straight now it should be good.

The plug will act like a tap and clean up any buggered threads. Good that you used a torque wrench on it.

From now on I will be counting the strokes on the ratchet handle as I take my plugs out and put them back in. A big part of being a mechanic is the feel of the wrench in your hand, knowing what feels right, and whats not.
 
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