Optional Short kit for 8mm inserts:
not recommended for inserts longer then 8mm,
use our standard spark plug kit.

M14x1.25 spark plug thread repair for short 8mm length
inserts.  We offer a kit that would have a standard
counterbore to create the countersink for the flange so
the insert sits below the surface. The kit would be used
for spark plugs that are NOT recessed. The spark plug
should be visibly near the surface.

p/n 66014125F would include 8mm length inserts.
Example: Used in Harley Davidson where the spark
plug thread length is 8mm using a Autolite spark
plug part number 86 measure your spark plug thread
length to be sure.   Many Harley spark plugs use 3/8
and 3/4 reach plugs which would be our p/n 6604412
kit with inserts p/n 66144125 for 3/8 and p/n 66144111
for 3/4.

Normally a special tool called "seat cutter" would be
used in our standard p/n 6604412 or 6604412E kits to
countersink and clean the seat operation but due to
some heads having shallow threaded spark plug holes
we can not use our standard seat cutter because of
the tap threading too far into the head.   We offer the
66014125F kits for the shallow spark plug thread
repair

The P/n 66014125F kit will include: Drill counterbore,
tap, tap guide, install driver and 5 inserts 8mm in length.
This kit will not be able to clean a new seat where
the washer will seat, it will only install an insert. 



 

Standard spark plug kits p/n 6604412 or 6604412E would
not work for short inserts.  See Step #2 found on standard
spark plug repair page, The tap must be threaded 1/4"
below the surface so "seat cutter" can pilot on the shank
of the tap. The tap would fall thru on short threaded spark
plug holes so optional kit p/n 66014125F is available.




Note: Kit p/n 66014125D would include 7mm length inserts