Cross threaded spark plug

[stampy69]

Hey guys i cross threaded my spark plug yesterday and wondering what size helicoil kit i need to try and re-thread it??

LIfan 125cc motor

spark plug is c7hsa, if that helps

 

[my67xr]

M10 x1mm is the thread.


have you tried running the plug back into the thread to correct it ?
or do you mean you have stripped the thread ?

 

[stampy69]

yeah, just made it worse.......first 4 threads on plug and head are gone.

I might try with a new plug, probably should've done that first!! lol

 

[my67xr]

if it is totally stripped from being over tighten then the Helicoil kit, or the Champion thread insert is the way to go.
but the best way to do it is to remove the head from the motor first.
http://www.ebay.com.au/itm/M10-X-1-...LH_DefaultDomain_3&hash=item20d62354e4&_uhb=1
http://www.timesert.com/html/sparkplug.html






or you could just replace the head too ?

 

[my67xr]

i have modified an old spark plug, to use it to run down crossed threads.

it is just a matter of using a thin 1mm cutting disc in an angle grinder and cutting a slot in the old plug,
cut it so the flat is on the left side, and the recess is off to the right, or copy the angles off an old tap.
you should be able to see it in my pic, it's a bad quality shot though!
all you need to do is to carefully run it down the thread, just to clean it up again.

 

[8r3nd0]

You never cease to amaze me Craig you tricky ****.

 

[my67xr]

You never cease to amaze me Craig you tricky ****.

haha,
i'm used to fixing stuff, been doing it most of my life due to neccessity, and a lack of spare cash!
being a self taught panel beater/painter/fabricator has helped me learn a lot of it too.