Can you fix this

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Oh, there's plenty of meat there. I saved an 066 jug once that had two failed spark plug thread repair attempts. I drilled it out and tapped 18mm threads and used a small block Chevy spark plug in it.

how did you make the taper J.J? that's an awesome redneck repair :laugh:. if i were WDO i would just chase the threads then thread the correct length heli-coil in there now with a bit of loctite. guy who originally did the repair probably didn't use loctite so the heli-coil backed out when he removed the plug.
 
i used a heli-coil in my very first 3120 back in 2007 and the thing is still holding like new. i have since swapped that top end onto my regular use mill saw.
 
I, ll try to get a better pic. It looks like it's a repair. The helical is very short
Not even the same length as the plug. It really needs an solid insert....not a helicoil. I go ogled and found big-sert. Not sure is something like that is needed or if a reg. Insert will work.
If you can source a Timesert kit i think you could fix it. IIRC the timesert is larger OD than helicoils & is a solid sleeve with a lip on the outer end. For a really bad one I have tapped out to 18mm(old spark plug size) & used an 18 to 14mm reducer
 
how did you make the taper J.J? that's an awesome redneck repair :laugh:. if i were WDO i would just chase the threads then thread the correct length heli-coil in there now with a bit of loctite. guy who originally did the repair probably didn't use loctite so the heli-coil backed out when he removed the plug

Definitely worth a try just don't the put the spark plug in until the Loctite has set might stick the plug to the heli coil
 
If you can source a Timesert kit i think you could fix it. IIRC the timesert is larger OD than helicoils & is a solid sleeve with a lip on the outer end. For a really bad one I have tapped out to 18mm(old spark plug size) & used an 18 to 14mm reducer


It looks like the timeset kit would be over run about $300. It looks like a great way to repair it. But not at that cost.
http://www.timesert.com/html/bigsert_sparkplug.html







.
 
Helicoils were common from the factory on older cylinders.
I bet that's an OEM helicoil and someone cross threaded a plug into it.
Can you blow the pic up a little more, I'm having trouble seeing it.....

No kidding? That's really interesting. I've seen a couple of older Stihl saws with helicoil type repairs that were done so well it took a second look just to realize it was repaired. Makes me wonder if they came from the factory like that...
 
No kidding? That's really interesting. I've seen a couple of older Stihl saws with helicoil type repairs that were done so well it took a second look just to realize it was repaired. Makes me wonder if they came from the factory like that...

Many came from the factory with Heli-coils already installed. Scarr pointed out that a properly done Helicoil is actually stronger than base threads cut into the same material. One example is the exhaust mounts on early 385 cylinders- they came from the factory with Helicoils.

Of course there's a population of people who've already convinced themselves that all Helicoils are bad...
 
Well, local auto stores have them kits for like 30$. I've been on the road this week and go right by the main head quarters for jc whitney. They have a retail counter there so I thought I'd check there. They had the save a coil kit for like 26$ and a no name kit for 17$. They had one no name kit all taped up without packaging they sold me for 9$. OK, I'M a tight a$$. The inserts with this have a shoulder that gives the plug washer something to seat on. I'm thinking of using red locktite on it. What do you think?
 
You don't want an insert that seats again the washer.
 

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