Loose spark plug advice

[Jimski]

Hello folks

So I went to change the plugs on my 1600 twin port today and I found that the plug on the front left cylinder was super tight.
The other all came out no problem but that one needed a load of force to get it to even move.
I eventually got it out and it looks like it had JB Weld (or similar) on the thread.

The new plug goes in but will not properly tighten, It doesn't come out but it feels a bit wobbly and loose.

Does this mean a stripped thread? Am I looking at a Helicoil to fix or should I replace the whole head?

Can I do any sort of fix with the engine in?

All and any advice gratefully received.

Cheers

Jim

 

[K@rlos]

A helicoil will be fine. I put them in all 4 on my old 1600

 

[subheatadey]

Forget helicoils, google Bigserts loads better

 

[Jimski]

thanks chaps

are they fairly easy to fit yourself on the street?

 

[subheatadey]

Your going to have to take the head off and avoid swarf so you can do it on the kitchen table whilst your watching telly I might be simpler to try and locate a decent second hand head with no cracks?

 

[Tony123]

Yep take the head off tried mine with head on instructions said rethread with TDC set thread is now gone head off damage revealed & plenty of swarf in chamber even after blowing it out with an airline

anyone think I can get the head saved thread is near to m16 size or a bigger spark plug after another re-thread ?







Sorry to jump on your thread

 

[Trikky2]

Yep take the head off tried mine with head on instructions said rethread with TDC set thread is now gone head off damage revealed & plenty of swarf in chamber even after blowing it out with an airline

anyone think I can get the head saved thread is near to m16 size or a bigger spark plug after another re-thread ?

I think its best to replace the head because the hole is now rather too close to the valve seat.
It's not worth the risk of the valve seat coming loose since it could then jam the valve and result in contact with the piston, wrecking the engine.