Buggared spark plug threads . . .

Dang, I've really done it this time, boys. Last night after checking the timing, regapping the points and checking the lifters, I decided to put in a new set of Bosch spark plugs. The back one went in by hand all the way. Torqued it to 20 ft. lbs. - manual says 18 to 22. The front one, I remember, gave me a little trouble the last time I changed plugs. Anyway, this time I screwed it in by hand a few threads and it started to grab a bit, but I was tired and wrenched it and it seemed okay. Got about half way in and it wouldn't go any further. I knew I buggared the hole and backed it out. I used anti seize on the plug threads.

I wonder if there is a way to get that plug in short of taking the head off and cleaning up the threads with a tap. I have read that sometimes you have to bore them out and put in an insert.

Check out thread chasers. Apply enough grease to it so it holds
any metal shavings.

Try this....I'm having trouble posting as a link.

https://www.denniskirk.com/283295.s...m_medium=cse&gclid=CIGE5eutvLICFcY7OgodY2UA0w

Thanks, Bikem, I will get one and try it. Oh, and BTW, welcome to Bike Talk. I think you'll find this forum friendly to any who ride.

A trick I just learned about is to get a piece of 1/4" clothesline and slather it with grease and stuff it down into the combustion chamber. Supposed to catch any metal that the greased tap might not catch. When done tapping simply pull it out the plug hole. Can also spray brake or carb cleaner into the hole and vacuum the particles out with a small flexible tube attached to a shop vac hose.

So, I'm going to try this method first. If it doesn't work, I'll have to helicoil the hole, which can also be done without removing the head.

Borrowed a spark plug tap from a friend and tapped the hole out successfully. First greased up a 3 foot long section of clothes line and stuffed it in the hole and also greased the tap.

Plug went in straight and seated properly. Rode 15 miles or so and everything seems okay. Still have a hesitation and cough from the carb so I'm going back to the "carb cough" thread. Thanks to all who chipped in with some advice.

Did you use any Anti Seize on the plug threads.

And what is the number on the spark plug on the old bike ?

Yup, I used anti-seize. I'm using Bosch plugs for shovelheads. I'm thinking of going back to the Champions I used to use. Since switching to the Bosch plugs the bike has been harder to start - especially after it's warmed up.

Look and try Autolites man. They work good in Harleys.

All the Indy shops here use autolite 4164
I have been running them for many years
Dude that graduated from MMI many years ago
Said autolite for Harley's , NGK for metric bikes

Autolite is better than champion

S.E. plugs seem to work fine and last long.IMHO

I thought you said the bike was easier to start with the Bosch plugs that tattoo reccomended you use? am I confused?

Se has more than one style plugs.
And SE Does Not make their plugs.

Autolite also has more than one style plug.


Autolite Xtreme Sport XS4164 - Spark Plug | O'Reilly Auto Parts

I don't remember where the thread was, Tommy. But I remember having hard starting with the Bosch plugs. Bosch recommends using their platinum plugs for shovels and Tattoo gave me a set of super plus. I like the Champions better - or rather - my motor likes 'em better. My bike definitely starts easier with the Champions, especially after warm up.

I've also heard that the Autolites were good, but never tried any.