Spark Plug Thread Repair
Ultimate HDF Member
Joined: Jul 2014
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From: MASS_hole
that. Plus a dab of tread lock can only help
Club Member
Joined: Sep 2010
Posts: 15,428
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From: Beyond Fucital
It's real easy, I did the first one in the parking lot of a daycare place.
A little lithium grease on the tap for heat dissipation and ot catch the shavings.
30K on the fist one and 13K on the second so far.
I'd skip the locktite though. They do recommend gasket sealer at the top of the insert.
The threads are your ground for the spark plug. No ground, no spark.
A little lithium grease on the tap for heat dissipation and ot catch the shavings.
30K on the fist one and 13K on the second so far.
I'd skip the locktite though. They do recommend gasket sealer at the top of the insert.
The threads are your ground for the spark plug. No ground, no spark.
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HDF Community Team
Joined: Dec 2005
Posts: 5,404
Likes: 2,605
From: NC USA
Ive used Helicoil many times when I owned Nortons and Triumphs in the 70.
I also had to repair sparkplug threads.
One of the bikes were a 70 Commando with high compression pistons and a 4S cam.
That engine is still running strong with the insertion repair threads in the head.
I bought a kit with a set of different sizes of drillbits and repair threads and a tool.
Had good use of that kit for many years.
I also had to repair sparkplug threads.
One of the bikes were a 70 Commando with high compression pistons and a 4S cam.
That engine is still running strong with the insertion repair threads in the head.
I bought a kit with a set of different sizes of drillbits and repair threads and a tool.
Had good use of that kit for many years.
"And YD, the el cheapo set you used, was it similar to the time-sert style but with a different installer?"
The set I picked up about 20 years is made by "Perma-Plug, from a farm and fleet store on sale for about 15 bucks.
https://www.walmart.com/ip/Perma-Plu...-Kit/199947031
It is the stake in place style, so might be a little risky with the evo head. Never had a problem with it backing out of the triumph head, but always wondered if it would I used red loctite when installing (along with staking it in per the directions) but with the heat, the loctite probably didn't help any in regards to holding it in place.
Do you have any planned down time with the bike? If you need the bike up and running then helicoil until you have some down time to get it welded up. There is a helicoil kit on amazon for 25 bucks. YD
The set I picked up about 20 years is made by "Perma-Plug, from a farm and fleet store on sale for about 15 bucks.
https://www.walmart.com/ip/Perma-Plu...-Kit/199947031
It is the stake in place style, so might be a little risky with the evo head. Never had a problem with it backing out of the triumph head, but always wondered if it would I used red loctite when installing (along with staking it in per the directions) but with the heat, the loctite probably didn't help any in regards to holding it in place.
Do you have any planned down time with the bike? If you need the bike up and running then helicoil until you have some down time to get it welded up. There is a helicoil kit on amazon for 25 bucks. YD
Yeah, self inflicted unnecessary downtime
If it was mine, and I had the head sitting in my hand(s), I would bring it to an automotive machine shop and have them weld it up, drill and tap it. If it was still on the bike, I would put the piston at BDC, fill the cylinder with shaving cream, put in a helicoil or timecert, (probably helicoil because they are more readily available), crank the motor to blow out the shaving cream/chips and ride on.
Met a guy at Sturgis,...........
Met a guy at Sturgis,...........
And if I get the other work done before I decide on the plug hole fix, I'll run it till next year and try to find that guy somewhere between Arkansas and Sturgis. I hear he's proficient at replacing valve guides in the motel parking lot. I'm sure he could fix it!
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,198
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From: NW AR
A minor inconvenience. Not like it was serious or anything.
If my health issues don't get better, don't think I'll make Sturgis next year if I wanted to. Swing on through Fayetteville and I'll buy you a beer.
If my health issues don't get better, don't think I'll make Sturgis next year if I wanted to. Swing on through Fayetteville and I'll buy you a beer.
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HDF Community Team
Joined: Dec 2005
Posts: 5,404
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From: NC USA
I hope I got at least one more (good) road trip in me so, I hope to take you up on that
Road Master
Joined: Jan 2019
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From: Texas
Had a specialist fly in from Cali once to put 4 new inserts he custom machined in blownout plug holes on our 2000 F250 once. He rotated until exhaust valve was fully open on the cylinder in question and had a shop vac duct-taped to exhaust pipe. Verified cleanout with small borescope. Worked great. Ken
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From: In my head
My neighbor has a race shop I go to all the time, he's on the "Street Outlaws" show on television, runs 200 MPH small tire cars. Anyway, he gave me the helicoil for the trans on my evo but while we were at his shop he was showing me the setup he uses for spark plugs. Apparently blowing plugs on the big 500 inch + nitrous motors is a common thing. He brought out this loctite (green) and told me to never use it on anything that you ever plan on taking out, it's 100% forever, like welding.
I don't think they were Time Serts, it might be something else. If you want I can go ask what they are and get back to you. Let me know.
I don't think they were Time Serts, it might be something else. If you want I can go ask what they are and get back to you. Let me know.
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Joined: Jul 2014
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From: MASS_hole
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From: Michigan 15 Minutes East Of Hell
Knock on wood, none of my Triumphs has a single thread repair. But I've never found a glue that would keep the reflectors on my Trident so they have steel cable lanyards to keep from losing them (again)
I'm not so keen on the idea of staking them in, on this deal anyway. Pulled #2 today looking for another issue that wasn't there. So I guess I'll pull #1 tomorrow, drag out my plates, hone and Nuway cutters and do the top end.
Yeah, self inflicted unnecessary downtime
After 5-6 dry shaves standing in formation in sub zero weather, I decided I never need to buy shaving creme again. But it will suspend metal chips for sure!
And if I get the other work done before I decide on the plug hole fix, I'll run it till next year and try to find that guy somewhere between Arkansas and Sturgis. I hear he's proficient at replacing valve guides in the motel parking lot. I'm sure he could fix it!
I'm not so keen on the idea of staking them in, on this deal anyway. Pulled #2 today looking for another issue that wasn't there. So I guess I'll pull #1 tomorrow, drag out my plates, hone and Nuway cutters and do the top end.
Yeah, self inflicted unnecessary downtime
After 5-6 dry shaves standing in formation in sub zero weather, I decided I never need to buy shaving creme again. But it will suspend metal chips for sure!
And if I get the other work done before I decide on the plug hole fix, I'll run it till next year and try to find that guy somewhere between Arkansas and Sturgis. I hear he's proficient at replacing valve guides in the motel parking lot. I'm sure he could fix it!
Tourer
Joined: Apr 2009
Posts: 307
Likes: 108
Helical inserts work fairly well but got replaced in aviation by barrel inserts for good reason. Before keyed plug repair inserts were common my mentor (USAF jet, recip and AC-130 crew chief who retired in '74 to restore Vincents and other Britbikes) showed my a useful trick with Timeserts. We notched the top flange half the diameter of a finishing nail, installed the insert, drilled slightly undersize then JB welded the hole and tapped in an appropriate length pin cut from the finishing nail. First time he showed me was in 1985 and we did many since with zero problems. It's smaller in overall diameter than a keyed insert for where that matters but he did it because helical inserts backing out gets old. (Users like to overtorque plugs and helical insert grip relies on one end of the insert plus friction.) An advantage of Timeserts is if one messes up they make Big-Serts but since I've always pinned Timeserts I've never needed one. For non-spark plug holes I prefer keyed inserts (you can get a variety including those which use standard taps to install from McMaster-Carr, MSC and Fastenal etc but check Ebay for those part numbers first to save money) where wall thickness allows.