New 1984 125m, stripped spark plug hole

[MulletMan420]

So i received an e mail from the guy i bought the 350x from. He had this 125m, i was actually supposed to look at it this past summer, and he said he wanted $100. It is in pretty decent shape. The only red flag i had was that it had no spark plug in it. Well when i got home and tried to put one in i realized that the hole was stripped out. I can get the plug in about half way before it wont go in easily. So it is really looking like i am going to need to get a cylinder head for it. I have also heard of using healy coils, has anybody had any experience with them? Or should i try to retap it?
https://www.youtube.com/watch?v=PEwfay0LmYc

Here is a video of me picking it up and giving a look over of it. I try to give a good view of where it is stripped.

[cwolfe]

hey mulletman420 i would just run a tap through it. if it goes in half way then the threads can probably be cleaned up just make sure you have the correct short plug i have gotten six of those over the years with a bent valve from the wrong size plug. also you could get a bigger diameter plug and tap it for that just use washers to get the correct length so it wont hit the valve i have used honda 200 plugs for 110's with wahsers for clearance when the plug hole threads were gone. anyway i hope this helps and it is cheaper than heli coils and replacement heads.

[f76]

Spend the money and use a heli coil kit.

[MulletMan420]

I think i am going to try retaping and if that does not work i might buy a new head. There are quite a few of them on eBay for decent prices. Just wondering, how much do heli coil kits usually cost? I was very suprised when i found the 125 uses the same size plug as my 250sx

[trike savior]

here is what you need. they work great. my local o'reilys had it in stock but can order it too. specifically for spark plug holes, also quicker and cheaper than a new head.

http://www.oreillyauto.com/site/c/detail/HEL0/533414/N2377.oap?ck=Search_heli+coil_N2377_-1_4018&keyword=heli+coil&pt=N2377&ppt=C1986

make sure intake and exhaust valves are closed, and piston at BDC when you tap the hole bigger with the tool it comes with. blow the cylinder out with compressed air to get any metal shavings out or vacuum with small hose taped on works as well. the directions suggest gasket maker on the insert threads but I like red Loctite better.

[wonderboy]

If you don't want to buy a heli-coil kit for the spark plug hole, then just take the head to a machine shop. Typical heli-coil job at the shop by me is $20. This should be less expensive than a new head. Also, in my opinion, the heli-coil (or timesert, depending on what the machine shop uses) will be stronger and less proned to cross threading in the future. The heli-coil is steel, so your spark plug wont be threading into aluminum anymore.

[Atc70noob]

this happened to my atc70 and I used an EZ lock to repair it to original threads. I removed the head to make sure it was installed straight and I havent had any trouble since. The only thing I did different from the instructions was I removed the factory threadlocker compound and installed it with red locktite. I just carefully install my plug now and Ive removed and installed it over 50 times without the ez lock coming loose. Ive also used ez lock to repair threads on a jeep axle spindle for the brake calipers with no issues. They are pricey but definitely stronger than the cast alloy the head is made of.

[YTZ drew]

If all else fails and you need a head, send me a pm, I have a good used head that I'll never use, and I will sell it CHEAP to any 3WW member in need.