spark plug thread

hey, i have a 1987 tomos sprint and i was changing my spark plug and ended up stripping the thread.

someone mentioned that i could get a kit to re-thread it.

i was wondering if that would be easy, should i go to a machine shop, or is there some part i can replace?

much thanks


Re: spark plug thread

ou can go to any atv/motocross/scooter shop and ask them to do an HELICOIL.

it happened twice to me, first time, it was my fault, 2nd time, i got the moped like that.

they usually charge me around 10-12$


Re: spark plug thread

you'd want to remove the head, drill the stripped hole out to a proper size for the insert (nice and straight.. a drill press would insure this) Then tap the new hole to fit the threaded repair-insert (which has to be chosen properly) Then an insert installation tool would be used to drive the insert in.. i left out a few details. the kit alone is gonna be about $30, probably more..

the part you could replace is the head, which might even be cheaper than doing it yourself.. but it seems like a no-brainer to pay someong to repair it for you if, as g.b. says, it can be done for under $20..

Re: spark plug thread

John Joedicke /

When you say stripped the thread or do you mean cross threaded. You could just chase it with a 14 mm sparkplug tap and clean it up. Worth a try first before you go to the heli-coil setup.

Re: spark plug thread

Don Pflueger /

take it to a machine shop, lawn mower repair shop, auto repair shop, or motorcycle shop and let them install a 14mm heli coil to repair the threads.

Re: spark plug thread

I prefer Tyme-Sert repairs for spark plug holes.. they seem tougher, and unlike a heli-coil, there is never any danger of the insert falling into the cylinder.

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