If you have a cross threaded 12mm x 1.25mm spark plug in an Aluminium head, then this is the perfect little kit to rectify it.
The tap gradually cuts the 12mm thread, slightly wider so that the thread is cleaned up, and you can fit the machined aluminium insert into the spark plug hole.
The inserts provided in the kit have a stop at the top so once you have selected the length of insert you need it will stop when fully inserted.

Please Note:

Using these spark plug naming tables should help you check that you are purchasing the correct repair kit: Champion NGK Bosch

Specifications

* For aluminium heads
* For 12mm x 1.25mm spark plugs
* 1 x HSS tap for cutting the new thread
* 4 x inserts
* Insert Lengths: 9.5mm (3/8''), 11.5mm (7/16''), 12.7mm (1/2'') and 19mm (3/4'')
* Inserts have an end stop

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