# bad threads in sparkplug hole



## wood butcher (May 11, 2009)

well i was checkin my plugs after a jet kit install and was putting in rear plug and it crossed threaded , i backed it out and tried it again and now it just eats the threads right off the plug after giong in only 1/4 inch . does anyone know the tap size for the plug hole ?


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## 1970chev (Jun 4, 2009)

i believe it to be 10mm x 1.0 tpi, that is what i used on my 750??:aargh4:


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## phreebsd (Dec 16, 2004)

the thread pitch is 1.0
verified with thread pitch gauge


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## FABMAN (Dec 18, 2008)

It would be best if you can get a hold of a spark plug tap. It taps from the inside out so you don't get shavings down in there.


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## phreebsd (Dec 16, 2004)

i have not heard of those fabman. i learn something new daily 

i have found thread chaser for spark plug hole










a whole spark plug repair kit


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## wood butcher (May 11, 2009)

hey phree where did u find that at


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## phreebsd (Dec 16, 2004)

i googled 

spark plug tap


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## wood butcher (May 11, 2009)

ok heres the word----- its hot as hello out side right now but anyway i got it fixed the tap size is 10mm x 1.0 thread pitch , had to remove belt cover and shift arm to get enough room (that rear plug is a biotch to get to) while im in there belt seems to be a little low in the secondary so i'll be adjustin it now . thanks guys for the info


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## FABMAN (Dec 18, 2008)

hears the back tap i found it on jegs. $35. it dose come in several size's and 10mm , 12mm , 14mm, and 18mm. I'm sheer it comes in fractional to











The Back-Tap cleans threads from the inside out by compressing smaller than the threads, as shown here. The mandrel is then drawn into the Back-Tap with the knurled nut at the top, expanding the threaded portion as in the main photo. By backing the expanded tool out from the bottom of the hole, the damaged threads at the top are restored.


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## 08GreenBrute (Jul 13, 2009)

i did that with my 05 when it was still pretty new and it scared the crap out of me but once i retaped it all was good


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## phreebsd (Dec 16, 2004)

tims 650brute said:


> ok heres the word----- its hot as hello out side right now but anyway i got it fixed the tap size is 10mm x 1.0 thread pitch, had to remove belt cover and shift arm to get enough room (that rear plug is a biotch to get to) while im in there belt seems to be a little low in the secondary so i'll be adjustin it now . thanks guys for the info


huh.. 
i picked up 2 plugs off my work table which i took for granted as being old plugs for the brute. They both had 1.0 thread pitch. 

for thread searching purposes and keyword search:
BRUTE FORCE SPARK PLUG HOLE 1.0 THREAD PITCH
TAP SIZE 10MM


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## wood butcher (May 11, 2009)

well i took one of my old plugs to napa and they checked the thread pitch for me and it is def 1.0 pitch 10 mm on the 650 brutes the 750 may take a different plug but the 650 is for sure 10mm x 1.0 i seen it with my own eyes, and used that tap and plug went right in


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## FABMAN (Dec 18, 2008)

mmmmmmmmmm I just checked mine and there 10mm 1.00 pitch


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