Stripped spark plug thread repair

[FlyingDutchman]

I have a useful but junky 575xp that ran great with a pretty clean looking oem cylinder. it was used for logging so it needs plastics and etc. Which is just fine for me.

We tried the insert (steel solid not a coil) repair and it didn't hold. Because I gambled on the insert, I've resolved I'm not spending more money or effort on it pulling it apart.

Im thinking about trying to solder the insert in place. Was wondering if anyone had tried it. Like sweating a pipe. With the dissimilar materials i don't if it would hold but it would be a last ditch before letting the parts hounds have it.

Thanks

 

[sean donato]

Solder won't hold up. Never had an issue with inserts made for spark plugs properly installed. Think we used timesert or something like that. The generic inserts don't seem to work well.

 

[FlyingDutchman]

Solder won't hold up. Never had an issue with inserts made for spark plugs properly installed. Think we used timesert or something like that. The generic inserts don't seem to work well.

I tried a higher end one from Napa, may have been a timesert. But the previous owner had already tried a cheap one which did its damage before I tried another one

Thanks for the info on the solder!

 

[Squareground3691]

https://www.mcmaster.com/key-insert...system-of-measurement~metric/thread-size~m14/

 

[cookies]

Timecert makes oversized thread repair kits , l could also suggest pulling the cylinder and taking it to a machine shop. They can tig fill that hole then drill and tap it back or they may have the timecert kits on hand.

 

[sean donato]

Timecert makes oversized thread repair kits , l could also suggest pulling the cylinder and taking it to a machine shop. They can tig fill that hole then drill and tap it back or they may have the timecert kits on hand.

I was going to suggest similar, but the shop I used to work for is up to $120 hr for jobs like that with a 1 hr minimum charge. Better off buying a new head then fixing it if the threads are that screwed up.

 

[sean donato]

I tried a higher end one from Napa, may have been a timesert. But the previous owner had already tried a cheap one which did its damage before I tried another one

Thanks for the info on the solder!

Should have come as a complete kit with special install tools if it was a timesert. Counter bore tool, tap, and a swedge tool. If I recall there was a certain for of loctite that had to be used with them as well.
Here found the kit we used. Pretty expensive.
https://time-serts.com/store/ford-special-m12x125-spark-plug-3-valve-kit-pn-4212h/They make many more different kits.

 

[ballisticdoughnut]

I tried a higher end one from Napa, may have been a timesert. But the previous owner had already tried a cheap one which did its damage before I tried another one

Thanks for the info on the solder!

I’m not a fan of the inserts Napa sells, they seem to be prone to backing out. They’re like a knock-off timesert. I’ve never had a problem with heli-coil or timesert repairs. They have to be installed correctly of course.

 

[FlyingDutchman]

There's people on this forum that do them for less than 120, last time quoted, 75 plus shipping. I already spent $50 on the insert deal (not as nice as the one linked here, for sure) and even tried a special spark plug with a washer instead of a taper seat. The solder just seemed like it would work.

 

[sean donato]

There's people on this forum that do them for less than 120, last time quoted, 75 plus shipping. I already spent $50 on the insert deal (not as nice as the one linked here, for sure) and even tried a special spark plug with a washer instead of a taper seat. The solder just seemed like it would work.

Your in replace the head territory imo. The insert kits are around $300.00 and $75 to fix something you've spent $50.00 on to fix when they are typically sub $200.00 doesn't make much sense. The solder just won't hold up in this situation.

 

[FlyingDutchman]

https://www.arboristsite.com/members/srcarr52.39776/ this is the cylinder fixing guy.

Yeah Sean, totally agree with you. I used to be more driven to fix it when this was the biggest saw I could get my mittens on. Now I've got a 576xp and a 385xp

 

[Jasonrkba]

Brisco on YouTube did one of the best repair jobs I've seen. Video is about a month old.

 

[ballisticdoughnut]

There's people on this forum that do them for less than 120, last time quoted, 75 plus shipping. I already spent $50 on the insert deal (not as nice as the one linked here, for sure) and even tried a special spark plug with a washer instead of a taper seat. The solder just seemed like it would work.

The gasket type spark plug is what it should have. Taper seat is going to damage the threads/cylinder.

 

[HansFranz]

No way solder is going to work on aluminum/magnesium. It won't adhere. Even welding that stuff is a biotch because it conducts heat so well. You need a BIG power source to weld aluminum for that reason.

Considering the time, effort and likelihood of failure involved, I recommend either a timesert gizmo or a new jug. (I'm a tig welder and might try fixing it just for grins, but I wouldn't have a lot of faith in getting it right. Things warp and distort and get arc-strike hard spots and do all kinds of funny things when you weld on them...and then ya gotta tap the hole again, yada yada yada, and then you spend the time putting it all back together and it doesn't work right. Better to just start fresh with a new jug and be done with it if your time has any value to you...YMMV)

 

[benelli7d]

As I peruse these threads and see how inexpensive saw parts seem to be. I'm totally blown away how cheap jugs and pistons are, it raises the question in my pea brain, why not just buy a new head? I'd think they too would follow suit and be very affordable. Certainly more cost effective than wasting all the time and expense trying to repair it, as referred to here in this thread.

 

[huskihl]

As I peruse these threads and see how inexpensive saw parts seem to be. I'm totally blown away how cheap jugs and pistons are, it raises the question in my pea brain, why not just buy a new head? I'd think they too would follow suit and be very affordable. Certainly more cost effective than wasting all the time and expense trying to repair it, as referred to here in this thread.

$75 to have it repaired better than oem vs $175 for new. Labor is the same other than boxing and shipping to srcarr52

 

[Lightning Performance]

$75 to have it repaired better than oem vs $175 for new. Labor is the same other than boxing and shipping to srcarr52

Steve has several to be redone as do I and few others asked me recentlyto fix aluminum threads in plug holes ripped out. I plan to close up the chamber area and not destroy anything with heat. Having a proper heat sink made to protect the plating, switching over to reverse polarity and a mini spool gun should work fine or another method like tig. The machine shop is only a stones throw away. I might even move the spark plug location on my 066 jug. It needed an insert and I don't like the fit or finish. Once the big threads insert pulls out your only left with pipe thread options and reducing the hole with water neck inserts made from brass so it can be reduced to accept a proper time cert or helicoil. Most people don't braze in or stake the insert so they pull out when hot. Not removing the plug when hot solves most of tuneup issues created after the repair and not torque the spark plug like it was a head bolt on inline six does help sometimes. The 200T is a prime candidate to reduce the combustion chamber area or the 066 thin base.

 

[Chevboy0167]

You could take a gamble..... would smell like chinesium tho....

https://www.ebay.com/itm/2951844465...O8KfLWioDncXNy6pivQDzV2A==|tkp:Bk9SR-rOuZm6YQ
Or the better but pricier options...


https://www.ebay.com/itm/1842831789...ZCSqz8v1mqlw4NPuS7FaJuoTAH|tkp:Bk9SR_LOuZm6YQ
https://www.ebay.com/itm/1738297211...FFo3zOOhm9WuLIhbVulBC2zUU+|tkp:Bk9SR_TOuZm6YQ

 

[cookies]

As I peruse these threads and see how inexpensive saw parts seem to be. I'm totally blown away how cheap jugs and pistons are, it raises the question in my pea brain, why not just buy a new head? I'd think they too would follow suit and be very affordable. Certainly more cost effective than wasting all the time and expense trying to repair it, as referred to here in this thread.

some of these oem cylinders are 300+ new or are nla. These repairs become important in the event you can not get a new or used cylinder.
It might even be worth making friends at a local autoshop and see if a trade for a case of beer to use the timesert kit they already own and maybe throw in the pack of 5 inserts that you will need for the 5 minute job at the end of the day when they are not busy.