Spark Plug Threads

[kernalklink]

Well i did it, i stripped out the threads in the head for my plug. well they were mostly stripped when i got it but i did her in. I have a honda 1985 act 110, i would like to know if anyone has good suggestions or, i have the oppurtunity to get a 1985 trx 125 head real cheap, will it work? i have a damn haynes manual and its pretty worthless doesnt cover the 4 wheelers anyhow. i would like it if i could just slap a new head on and be done with it but, i dont know if it will work.

please help me, i really need this 3-wheeler to keep me happy!

[hotroddal]

you can purchase a heli-coil kit and use that, instead of buying a new head.

[kernalklink]

yea but i can pick up the head for like 5 bucks from a friend but i dont know if it will work.... does anyone know how to determine helicoil size(if i have to go that route)?

[freewheel3]

Don't know about whether or not a trx 125 head would work but I would think twice about using a heli-coil for spark plug threads. I have used them in the past with mixed results. Yeah, the plug will tighten in there but the first time you go to remove it there is a chance that some of the heli-coil will fall into the cylinder & then you are screwed.
I'd look for a replacement head. Post an ad in the classifieds on here or of course, there is always ebay.

[max]

Freewheel Is Rite. I Would Just Get Another Head. I Wouldnt Want To Risk Anything Getting Down Into The Jug.
Max

[kernalklink]

yea i was worried about helicoil - it just seems wrong for some reason. i really would like to user a different head. if i do have to go that route how do you determine what size to use

[kernalklink]

helicoil size anyhow

[freewheel3]

yea i was worried about helicoil - it just seems wrong for some reason. i really would like to user a different head. if i do have to go that route how do you determine what size to use
Talk to your local dealer & ask him if they are interchangable. Or wait until one of the members on here can answer your question.

[kernalklink]

sweet i think i found a head though, thanks all for your input!

[bigredhead]

Will a hellicoil hold up to pressure from a cylinder ?

I know guys use them on oil drain plugs all the time.. but the tranny is not under much pressure......

what's the word on that ?

[freewheel3]

Will a hellicoil hold up to pressure from a cylinder ?

I know guys use them on oil drain plugs all the time.. but the tranny is not under much pressure......

what's the word on that ?
I've seen them used in several different spark plug holes in both aluminum & cast iron heads. Never seen them fail, in fact sometimes you can't get the damn spark plug out, heli-coil binds the threads up.

[kernalklink]

when i was looking into getting a helicoil they were made specifically for auto sparkplugs - so im sure they would hold up to the pressure... but i still dont see it as a valid solution. something about patching the head just worries me.

[bigredhead]

This is probably a very stupid suggestion.. so be forwarned.

How about having the plug hole tig'ed with metal coating and re-threaded ?

[slothminx]

yes a good helicoil if put in using the right tools and not just popped in will be fine and give you no problems. infact in the aluminium head on our car that has very high compression we have put a helicoil in without the thread breaking first just as insurance for the plug pulling the thread out at high rpm;) and yes big red head this can also be done but is not the best solution as the tig'ed in material can be weaker. but its not a stupid question :) lol whose gonna come out with i used jb weld :lol: :lol:

[TeamGeek6]

maybe have the hole bored out and weld a blank in, then bore through and thread it. Almost anything but a helicoil is a lot of trouble :(

I doubt JB Weld would hold that much pressure. :(

If you get desperate, get a longer plug and hold it in with a nut. Not a good idea, just an idea.

[OldSchoolin86]

yes a good helicoil if put in using the right tools and not just popped in will be fine and give you no problems. infact in the aluminium head on our car that has very high compression we have put a helicoil in without the thread breaking first just as insurance for the plug pulling the thread out at high rpm;) and yes big red head this can also be done but is not the best solution as the tig'ed in material can be weaker. but its not a stupid question :) lol whose gonna come out with i used jb weld :lol: :lol:
Well said sloth, a properly installed helicoil is a proffesional solution, not just a patch.

[Tecate performance]

if you use a helicoil, make sure the area around the hole is flat and clean or the plug won't seal well.

a company called time sert makes thread insert sleeves that are stronger than heli-coils. i've used them in bolt holes and on a 350x head that was already heli-coiled, but wouldn't seal properly. its a top notch product, but costs more than heli-coils. it was worth it for me though, saved me from buying another 350x head. it just takes a NGK B series plug now.