Helicoil for spark plug repair

[openspaceman]

Hi

 

I have done a helicoil repair to an alloy car engine cylinder head some years ago, worked fine, can't see why it wouldnt work on a chainsaw head

 

 

N

 

Me too but I cannot remember doing a saw spark plug. The main issue is not the coil coming back out but rather it screwing into the engine, so first make sure the helicoil is not longer than the plug thread and next do not run the drill and tap all the way through.

[spudulike]

Me too but I cannot remember doing a saw spark plug. The main issue is not the coil coming back out but rather it screwing into the engine, so first make sure the helicoil is not longer than the plug thread and next do not run the drill and tap all the way through.

 

I use a bit of Loctite 270, once the insert or hellicoil is in, it will NEVER come out:thumbup:

[Mark_Skyland]

Thanks for the replies and info.

 

I used a v coil repair kit, it came with a thread chaser tap which guides the tap. AFAIK they are a good kit, ive used v coil on plenty of other threads from m2 on RC helicopters to m18 on chippers and not had a problem, hopefully its up to the job on this one.

 

I did try to repair the thread with a thread chaser and thought I had it but after warming up the plug spun while tightening so decided to pull it apart again. I think I will buy a more expensive chaser that you insert then expand so it chasers the thread from the good end.

 

Mark, the thread is the same size so you use the same type of plug.

 

Started the saw up today and gave it a couple of revs, good enough for me. sniff.

 

Just for reference I had to use 1.5d inserts but I had to trim 1 and a half coils as it was too long.

 

Poxy little spark plugs:001_rolleyes:

[openspaceman]

I use a bit of Loctite 270, once the insert or hellicoil is in, it will NEVER come out:thumbup:

 

I do use loctite stuff but can never find it when I need it, last one I was trying was the solid stick, wipe the thread on it and go with no dripping, used it once and now...

[aspenarb]

I found the best results are when the helicoils are a couple of threads longer than the plug. If the plug has any exposed thread hanging in the combustion chamber carbon can build up on it, when the plug is undone the carbon will bind on the insert and it will unscrew.

 

Bob

[spudulike]

Thanks for the replies and info.

 

I used a v coil repair kit, it came with a thread chaser tap which guides the tap. AFAIK they are a good kit, ive used v coil on plenty of other threads from m2 on RC helicopters to m18 on chippers and not had a problem, hopefully its up to the job on this one.

 

I did try to repair the thread with a thread chaser and thought I had it but after warming up the plug spun while tightening so decided to pull it apart again. I think I will buy a more expensive chaser that you insert then expand so it chasers the thread from the good end.

 

Mark, the thread is the same size so you use the same type of plug.

 

Started the saw up today and gave it a couple of revs, good enough for me. sniff.

 

Just for reference I had to use 1.5d inserts but I had to trim 1 and a half coils as it was too long.

 

Poxy little spark plugs:001_rolleyes:

 

Yup, the Vcoil kit is generally good and I also grind to size to ensure a good fit.

[NFG]

Hi Mark,

 

Good effort & well done for fixing it

 

Thanks Spud ref the Locktite 270 & Openspaceman about the length - noted.

 

 

N