Snapped off spark plug??

Joined
Sep 23, 2010
Messages
23
Well, in addition to my recent Commando project, I just picked up yesterday a 70 BSA Thunderbolt project. Wasn't looking but was very close by so why not. Put it aside until the Commando is done. Anyway, get it home yesterday and was just gonna pull the plugs and put some MMO in the cylinders. First plug came out as easily as expected, but the other would not budge. Put some penetrating oil around the plug and called it day. Today go home at lunch, put another shot of oil on the plug. After work CRC freeze penetrant, allow sit for a bit. Try again to loosen the plug and then - snap. The plug breaks off clean, flush with the hole.
So now what? Off with the head and on to a machine shop? Don't know much about BSA, so will learn as I go - after the Norton.
Thanks for any thoughts!

In case anyone wants to see what I stumbled upon:
http://picasaweb.google.com/Cobyboss/19 ... underbolt#
 
Remove the head. drive the ceramic out of the middle of the broken spark plug. Heat up the head. Use an 'easy out' to unscrew the plug threaded bit. Helicoil (ONO) the threads in the head.

Greg
 
Nice pictures, but have to say you are pretty ambitious. I can't bring myself to do projects like that anymore due to male menopause............ :lol:
 
You'll be taking it apart anyway just to see what the condition of the top end is, so no big deal. If it doesn't have a lot of miles or abuse, the bottom is probably good to go and not worth splitting the case.
 
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