how to save a boogered up spark plug hole thread?

[Iahawk]

well...my Nighthawk 650 has been in pieces all summer. Today I decided to take my 3rd try at getting cams, sprockets, etc. back in with the correct timing. I successfully got everything installed and timed correctly! I was so happy. Started to put spark plugs back in and plug #3 was not going in easily by hand like the other 3. even with a ratchet on it it was taking more force than I was willing to put on it to get it back in. Removed and retried , gently, a few times. No luck.

Took a pic down the plug hole and you can see the threads messed up a little about halfway down. Ive posted this on my Nighthawk forum but thought I'd post here, too, as this is a relatively common engine problem. Any suggestions on how to proceed?  Thanks!  (hope Ruffus knows this forum is back online...)

[Iahawk]

all right, looks like I've found a solution...a back tap thread repair tool, for spark plugs! It is inserted in the plug hole, expanded then pulled back out while turning to chase the threads. It captures any metal because it is pulling out of the hole, not going in. Brilliant. Learn something new every day!

[Neil955i]

That sounds like a neat tool Hawk.

[Stig / Major Tom]

Is it removing much material?
Stig

[Iahawk]

I don't think it is supposed to, as it is only a thread 'chaser' or 'restorer'...not a full on 'tap' which cut new threads.

Directions say to put grease on threads so it will hold any shavings it creates as you pull the tool up and out. Might give it a try tomorrow...Saturday and Sunday are already booked solid.

[Iahawk]

great news...after almost 3 full months being out of commission and unrideable, the Nighthawk lives again! Got the sparkplug hole threads chased and cleaned up so a plug would screw in easily by hand. That sparkplug tool worked great. Highly recommended if anyone messes up sparkplug threads.

New cam chain tensioner spring installed, cams, sprockets, oil pipes and cam holders installed for the 3rd time (and lifters bled 3 times, too). Timing was dead on, finally. Got everything put back on (coils, plug wires, tank, side covers, seat and tank).

Took a few lengthy pushes of the starter button but she fired up and sounded great. No more cam chain slapping!

3 long months without my favorite bike during riding season.... but she's back!