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Stripped Spark Plug Hole

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Old Jun 8, 2021 | 04:13 PM
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Default Stripped Spark Plug Hole

If you somehow strip the threads in a spark plug hole like I did, don't panic.

Find an M10x1 thread chaser, coat it with grease to limit any shavings dropping into the cylinder, and see if you can repair the threads. Be careful not to run it in too far, if it falls into the cylinder you might say bad words. Also, make sure to clean the threads afterward with a rag soaked in Brake Kleen or something to get the grease out as much as possible.

I got lucky, and was able to torque the new plug to 110 in lbs with no issues.


 
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Old Jun 9, 2021 | 06:03 AM
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It did that taking it out? Was it the right rear plug? When I changed mine and was putting new ones in the right rear seemed like the threads were not as clean as the other 3. Went in and torqued but had more resistance.
 
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Old Jun 9, 2021 | 07:05 AM
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This was the left front, and yes it came out that way.

Working it back and forth didn't help any, so I just pulled it. The top 3/16" or so of the threads in the head were shot.
 
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Old Jun 9, 2021 | 07:27 AM
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How many miles do you have? And was this the first time you changed them out?
 
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Old Jun 9, 2021 | 07:37 AM
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I last changed them at 17k, and I have 31k on it now.
 
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Old Jun 9, 2021 | 08:29 AM
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Well that sucks ***...that's something ya never want to see. Glad you got it straightened out though.
I use Never Seize on plugs (and everything aluminum getting a bolt or screw) and cringe at the thought of Loctite blue and never use red in aluminum, but that's just me.

How's the tune running Larry??
 
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Old Jun 9, 2021 | 10:42 AM
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Originally Posted by plongson
Well that sucks ***...that's something ya never want to see. Glad you got it straightened out though.
I use Never Seize on plugs (and everything aluminum getting a bolt or screw) and cringe at the thought of Loctite blue and never use red in aluminum, but that's just me.

How's the tune running Larry??
It's running great.
 
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Old Jun 9, 2021 | 12:34 PM
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It has been been known to happen if you remove plugs while the engine is still hot. Not saying you did, but just mentioning it.
 
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Old Jun 9, 2021 | 08:31 PM
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Happened to me on my 2002 Fatboy. Had to put Helicoil in and it ran great for years after.
 
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Old Jun 9, 2021 | 08:43 PM
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Played this game many a time, my kit just for fixing spark plug holes. Got the thread chasers too for the salvageable ones still on the bike.



 
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