Spark Plug Threading all messed up

[djg42]

I just got a new GS project bike, I too the spark Plugs out and when I was going to put them back in, they wouldn't go back in and the threading inteh engine is visible deformed. Ive never dealt with this before, where do i go from here? I saw some repair kits online, any suggestions as to which kind to get?
Thanks!

 

[JEEPRUSTY]

Previous owner did not wwant the plugs coming out by accident eh?

If the threads are there and just bunged up a bit you could likely chase them with the correct tap.

 

[Suzuki_Don]

Just ask Graham!!

 

[Buffalo Bill]

Doh!

Doh!

I messed up the threads in one cylinder myself once, by rushing the plug back in with a socket and extension. I should have started the plug with bare fingers, as I already knew!
I found a spark plug chaser at the NAPA auto parts store, and used that to re-tap the threads. It's a thread tap just for plug holes.
To use it: Line it up as best you can figure, screw it in until it starts to bind, back it out a revolution, than go forward again until it binds. Repeat the process again. Do this until it reaches the bottom, you're finished.
Not the end of the world, yet.
Bill

 

[Texas Don]

+1 on the spark plug thread chaser tool. It's fairly inexpensive and will do the job properly.

 

[posplayr]

It is best to always start tightening your spark plugs with a high speed impact wrench




























NOT

Finger tighten only and you take your chances if you use a wrench before the plug starts to bottoms.

 

[tom203]

+1 on the spark plug thread chaser tool. It's fairly inexpensive and will do the job properly.

Yeah, and put a little grease on it to catch those chips!

 

[BassCliff]

Hi,

I had to repair a spark plug hole thread on my bike. CLICK HERE to read my thread. The thread chaser I got at the local auto parts store worked fine.

Thank you for your indulgence,

BassCliff

 

[JEEPRUSTY]

Hi,

I had to repair a spark plug hole thread on my bike. CLICK HERE to read my thread. The thread chaser I got at the local auto parts store worked fine.

Thank you for your indulgence,

BassCliff

Oh my a thread thread! Such serendipity.

 

[mighty13d]

Don't think that just because you chased the threads with a tap that everything will be okay. If there has been too much meat removed for the threads to bite into, you will end up with a spark plug that either strips the threads out when you tighten it down or even worse, goes flying out when the engine is running.. If you have any questions, get a threaded insert to repair it properly. Something from an auto parts store that looks like this:

which of course is not cut in half such as this one is. They are really easy to install and will work a ton better than a heli-coil. Heli-coil does make an insert such as this though. Do it once and never worry about it again. Just make sure to follow the directions exactly and use locktite.

 

[Ranger]

Don't think that just because you chased the threads with a tap that everything will be okay. If there has been too much meat removed for the threads to bite into, you will end up with a spark plug that either strips the threads out when you tighten it down or even worse, goes flying out when the engine is running.. If you have any questions, get a threaded insert to repair it properly. Something from an auto parts store that looks like this:

which of course is not cut in half such as this one is. They are really easy to install and will work a ton better than a heli-coil. Heli-coil does make an insert such as this though. Do it once and never worry about it again. Just make sure to follow the directions exactly and use locktite.

Requires removal of head from engine & drilling out to correct size to tap and install?

I have a cross threaded plug on my # 4, wanna fix it but a tap is too short and awkward to fit without pulling the head which I'm way to lazy to do.

 

[JEEPRUSTY]

Requires removal of head from engine & drilling out to correct size to tap and install?

I have a cross threaded plug on my # 4, wanna fix it but a tap is too short and awkward to fit without pulling the head which I'm way to lazy to do.

I saw some very long repair taps in a web search.

made for deep well cylinder heads on DOHC car engines.
Pricy but way cheaper than a head gasket plus the time to do a partial tear down.

 

[Ranger]

I saw some very long repair taps in a web search.

made for deep well cylinder heads on DOHC car engines.
Pricy but way cheaper than a head gasket plus the time to do a partial tear down.

JEEPRUSTY, what do you think of these?
http://www.mytoolstore.com/kd/kdengi11.html

Seems like you can start it by hand then use the socket to finish it.

 

[mighty13d]

Requires removal of head from engine & drilling out to correct size to tap and install?

I have a cross threaded plug on my # 4, wanna fix it but a tap is too short and awkward to fit without pulling the head which I'm way to lazy to do.

mine didn't. Just use some heavy grease on the tap to catch the filings. You MIGHT need to loosen up the engine to get a straight shot on it though. otherwise you're all set. Mine had a tap that threaded into the original threads and pulled down a cutter and then tapped the correct larger threads for the insert all at once. just make sure it's in straight and you're all set.

 

[JEEPRUSTY]

JEEPRUSTY, what do you think of these?
http://www.mytoolstore.com/kd/kdengi11.html

Seems like you can start it by hand then use the socket to finish it.

yes and heck if you wanted to have more depth you could maybe epoxy the hex head into a deep socket.

I know my redneck methods make people cringe but I would do that to a 30 dollar tool to get the reaach before shelling out more for the long ones.

KD tools makes long one I think

 

[Ranger]

yes and heck if you wanted to have more depth you could maybe epoxy the hex head into a deep socket.

I know my redneck methods make people cringe but I would do that to a 30 dollar tool to get the reaach before shelling out more for the long ones.

KD tools makes long one I think

I don't mind destroying a tool that I have more than one of to make something work. Not really worried about the depth, I don't plan on having this bike past summer so maybe 2 more plug changes are in store.

 

[djg42]

thanks for the advice!
So first I should just try and re-tap , using one of these-http://www.denlorstools.com/home/dt1/page_15542_273/kd_tools_kd_3379_spark_plug_thread_tool_14mm.html

and if the threads are already to messed up i should use a thread repair kit?
To use a kit like this do you have first drill the spark plug?
How does a kit like this work, it says no-drilling required?
http://shoptoolsshoptools.com/shopexd.asp?id=779

 

[mighty13d]

ok, that works exactly like mine did. the expanding/threading tool just threads down into the hole into the old threads as much as possible. then when you are twisting it down in, the remaining threads will pull it down into the hole and it will cut out a larger hole and then thread the new diameter all at once. Just turn it in some until it binds a little, back off, turn in more, back off, it's easy. Put a little grease on it to catch the shavings. Then once your hole is threaded properly to the larger size, check which insert to use and test fit it. Then put some locktite on it and thread it into place. Then use the expanding tool (it goes in the unthreaded end of the insert and you give it a solid smack with a hammer to expand it into place so it locks it's self in) and you're all done. Wait a full 24 hours for the locktite to cure before firing the bike up. Also put a little never seize or antiseize on your plugs prior to putting them in. The copper based is the best for hot places like that if I remember correctly. (it has a copper colored tint to it instead of silver) Then you're all done.

 

[djg42]

that makes it clearer, thanks!

 

[ddaniels]

Yeah, don't worry about it. It's an easy fix and you'll never have to worry about it again.