UL spark plug repair

[Flathead Jedd]

I've got a 47 UL with aluminum heads. As I was riding southbound, my spark plug went eastbound. It blew right out of the insert. The motor is rebuilt and the front head has an insert in it for the plug. I assume this was to repair damage. The insert appears to be aluminum and is approz 1 3/4" diameter. It threads into the head. No damage to the threads there. The 18mm plug screwed into to center of the insert. It's those threads that gave out. Does anyone know a good source to obtain a new insert? I'm not as dumb as I seem, but this is out of my relm of knowledge. Any help would be appreciated. Have a happy New Year.
Jedd

[Ohio-Rider]

Jed, I'm not sure if the insert your refering to is a helicoil insert or not. An 1.750 thru diameter seems awful big to be a conventional helicoil. Can you post a photo.-Steve

[charlie frey]

V-Twin has a Heli-coil kit in their catalog, but it comes with 24 inserts and retails for almost $200.

[exeric]

Auto Zone used to carry HeliCoil sets, and I know they had spark plug inserts. Much more reasonably priced than V-Twin.

[Flathead Jedd]

Thanks everyone. It does not appear to be a standard type helio coil. I'll take some pics of it soon to see if that helps.

[charlie frey]

I don't think the one V-twin sells is a standard "spring" heli-coil either.
I think it's a solid insert with a knurled collar on top.
I've installed similar ones using red loctite, then staked with a punch around the top.
Still have them in my UL.
NEVER remove plugs from a hot head.
The inserts can come out with the plug.

[AdminGuy]

anti-sieze on the plug threads is a good idea.

[Flathead Jedd]

Well I took a picture of the insert. I hope this helps identify the part. It has been recommended to me to just helicoil the insert, but if I can get the insert cheaper than the helicoil kit it seems like a better fix. Let me know, thanks again.
Jedd

[motorhead1]

Look here http://www.timesert.com/html/bigsert_sparkplug.html
You can buy the inserts only. This appears to be what you have.

[Chopperdave]

Flathead Jedd!

hi jedd
that repair kit above this post is for 14mm plugs, not the 18mm ones...
but the timesert kits are THE BEST for repairing threads, PERIOD.

i believe what you have is a repair piece that isnt made anymore,
i have seen those inserts before as well, once in a 45 and also in a 74
call me on monday, after 1, if my guy has the tap for it, I can machine a plug for it and weld up your head and remachine it...

otherwise you could get the helicoil kit from vtwin, but either way, id suggest pulling the head off, if you are going to helicoil it, we need to fully clean the threads so the insert could be reloctited in place...
but i bet that insert is steel...


on another note, went to chino airport today, got to see a p-38 fly... and a p-47, and a hellcat and a corsair.
neato....
and took lots of pix of radial engines, if i went with another motorhead freak id a been there all day, but dre thought we were there for 3 hours and we had only been there for 1.5 hours!

and Jedd, we need to go surfing...

[Paps]

Try Napa. Paps

[P LaLonde]

Jed, If by chance you are looking for a different head,i have a front only,in near perfect shape ,excellent thread hole. I was going to use it on my 38,but never found a rear.Good Luck
Paul

[mmoore]

from past experence I always avoid heli-coils stop by a good machine shop and see what is available I picked up some hardened inserts to repair my 34 flathead. the head bolts were stripped enough to scare me but these were only about 70 cents each. they need to be locktited but I also staked them. I use these on all my thread repair (for the last 20 years) and never had a failure yet. (I owned my flathead for 20 years now) as previously mentioned tho I also use antisieze on the bolt after the locktite sets up

[Flathead Jedd]

Thanks everyone for their help. Chopperdave is repairing the head for me. We are just going to replace the insert with a new piece of metal and retap a new 18mm plug hole. Might as well do it right, afterall the beauty of the side valve is it's simplicity. Thanks until next time.
Jedd