Stripped spark plug hole

[Icculus88]

I have a 79 gs 750 and I went to swap plugs out today and when putting the last one in it immediately did not want to go, i forced it about a have a turn and it began stripping the threads in the hold. I am afraid i will have to replace the cylinder head, any ideas?

 

[JEEPRUSTY]

I think you can get a chaser and straighten the threads.
http://www.pjsmotorcycles.com/Jims-...Id=10873785&ez=Cruiser/V-Twin~q=isidaa4zz~r=~

far cheaper than a head removal.

 

[Nessism]

Install a spark plug thread insert. No need to remove head. Timesert is best. Solid type Helicoil brand inserts are passable. Lots of different threads in the archives on this problem.

 

[posplayr]

rule number one; NEVER FORCE THREADS on a ALUMINUM parts. ALWAYS start finger tightening.

If you only did 1/2 turn you probably just marred the first starter thread and you cant get it started.

You need to be careful with fine threaded aluminum. I try to always finger tighten my spark plugs down to the seat them, before using a ratchet to do the final tightening. You can use a socket and extension by hand to do that.

Now fork tops are tricky

 

[chuck hahn]

I did the number 3 on my 78 1000C in about 1/2 hr on the bike..I used the NAPA SAV-A-THREAD Kit. Part #770-3223..Size M14X1.25 Take a screw driver and be sure the piston is at the bottom and use the supplied tap on an extension. Carefully run it into the cylinder while having a shop vac sucking up as much of the shavings as possible. Once the tap has been run in and removed suck the shavings from the cylinder as you slowly bring the cylinder back to the top. Then use a compressor and spray down in and get as much shavings out as you can. Install the insert WHILE IT IS ON THE SPARK PLUG..TRUST ME ON THIS . Its much easier and then your bsaically done. Some high temp thread locker is suggested on the insert. The cost is aorund 49.99 and well worth the expense in my opinion.

 

[1_v8_merc]

Someone stripped the #1 hole on my 78 750 too.

But the hole has 2 different thread sizes

So I have to carefully insert the plug Down into the hole, and carefully catch the proper threading each time.


ALWAYS start the threads by hand....and start it very gently.
You have Plenty of room to correct your threading......don't sweat it.