plug blow out

[billy192]

Well, just got used to having oil droplets now and then on the outside finns went out for a ride and POP out blowes NO1 plug. got home on 3 and replaced with new plug but will not nip up v tight. it tightens but not as much as it should. got a feeling it will pop out again.

if it does then can you get helicoils to fit? if so what size would i need please? it seems just as you start enjoying the bike BOOOOM another issue. i suppose its engine out head off as a minimum.
happy bloody days
Billy

[Trigger]

Nope, you can not helicoil one. You need a insert to do the job.

[Bitsa (Ralph Wright - RIP)]

Billy
Many moons ago I have done helicoils on the plugs without taking the head off but never on the fours.Twins you can get away with it but fours I really would not take the chance.F ing bummer I know sorry mate you have to do it all again
Cheers
Bitsa

[Doc.]

Nope, you cannot helicoil one . . .

Why not?
A Helicoil is an insert anyway, or are you thinking of the more 'solid' machined inserts?


No reason it couldn't be fitted with a Helicoil, as long as there is enough good metal left once you've drilled out the damaged threads.
Could possibly be done in-situ, but you'd need to rig up some sort of drilling attachment to ensure you drilled the hole perfectly in-line with the original.
Much better to do it with the head off though, using a Milling machine, or a good pillar drill at the very least.

[billy192]

I have used heli coil lots of times but not for spark plug hole. i can't see why not
billy

[JamesH]

Nope, you can not helicoil one. You need a insert to do the job.

Guys listen to the man, he knows what he's talking about...

[Trigger]

Helicoils are only good for blind holes. For a non-blind hole your need solid insert. The helicoil will do the job but, what i have found is when you next remove the spark plug the helicoil will come out with it. Then you will have to get a solid insert. Better to do the job right the first time
If you have anyone local that reconditions cylinder heads, they will be able to do the job.

[Bitsa (Ralph Wright - RIP)]

Trig
Have to take your word for that but I have to say dont remember that happening back in the 70s.Bryan do you?
Cheers
Bitsa

[Trigger]

Bitsa, the best thing with using a solid insert is you can put it in with a little retainer. You can't use retainer on a helicoil.
1970 Bitsa? I thought back then you just wrapped a bit of tin foil round the thread and squeezed it back in.

[Bitsa (Ralph Wright - RIP)]

Trig
Fair enough mate as I did not keep up with technology of today all I can remember is back then.Can you update me with photos to my email address as I am curious to see this?
Cheers
Bitsa

[JamesH]

My understanding was that use of a Helicoil (stainless steel) in an alloy head was a bad idea, for spark plug holes because of the different material properties (coefficient of thermal expansion), especially in high temperature variance areas (i.e near the combustion chamber). Probably why the stainless inserts lose grip over time in the alloy head?

[Bitsa (Ralph Wright - RIP)]

Trig
Naw mate tin foil was used on fuses.Just kidding but you would not believe how many I have seen like that and also frac fuses just strip the ends and twist them together
Cheers
Bitsa

[Trigger]

James, you want to try and get the stainless steel spokes out of a wheel when they have used alloy nipples. That is when its time for the bolt croppers.

[Bitsa (Ralph Wright - RIP)]

Trig
You are a wealth of info all i can say is hmmmmmmmmmmm forgot about that
Cheers
Bitsa

[Trigger]

Bitsa, you did not order stainless steel spokes with alloy or stainless nipples? The best is nickle plated brass for stainless