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Spark Plug Thread Repair Kit Suggestions?

#1

l008com

l008com

Last Fall, I was winterising my equipment and I accidentally stripped the spark plug hole on my yard vacuum. Its a 31 year old machine and I didn't turn that hard, so its probably a failure that has been inching its way to happening for a while.

But no worries, this is a great opportunity for me to make a video about repairing stripped spark plug holes with helicoil type repairs. I used one of those to fix the brake rotor mount on my mountain bike and it worked great.

So the question is, does anyone have any specific suggestions for a specific kit (with links) that is good and that has everything you need in one kit. Including the drill bit UNLESS its a standard size bit. But I don't think it it, its probably bigger than 1/2" right? So the bit, the coil, the install tool, the thread tap etc.

I know I could also repair this by just replacing the head. But I'm making a video out of it so I really want to use a repair kit rather than a replacement head.


#2

R

Rivets

Here are two suggestions I have in my toolbox. Depending on how bad the thread are botched, will dictate which tool you need. If you purchase a kit, make sure it contains the proper length insert.

www.summitracing.com

Powerbuilt Tools 640811 Powerbuilt Back-Tap Spark Plug Thread Repair Tools | Summit Racing

Free Shipping - Powerbuilt Back-Tap Spark Plug Thread Repair Tools with qualifying orders of $109. Shop Thread Repair Kits at Summit Racing.
www.summitracing.com www.summitracing.com

You can google search “spark plug thread repair kit” to find a kit which best meets your needs. Drill size I use is .500”.


#3

A

Auto Doc's

What are the numbers on the engine.

I recommend removing the cylinder head.

You need to make sure you install the appropriate length insert to match the plug used in the engine.

Here is a good video:

Small engine 14mm spark plug rethreading - Search Videos

Watch videos instantly on Bing—enjoy direct playback, discover related clips, and dive into trending content all in one place.
www.bing.com www.bing.com


#4

Tiger Small Engine

Tiger Small Engine

l008com said:
Last Fall, I was winterising my equipment and I accidentally stripped the spark plug hole on my yard vacuum. Its a 31 year old machine and I didn't turn that hard, so its probably a failure that has been inching its way to happening for a while.

But no worries, this is a great opportunity for me to make a video about repairing stripped spark plug holes with helicoil type repairs. I used one of those to fix the brake rotor mount on my mountain bike and it worked great.

So the question is, does anyone have any specific suggestions for a specific kit (with links) that is good and that has everything you need in one kit. Including the drill bit UNLESS its a standard size bit. But I don't think it it, its probably bigger than 1/2" right? So the bit, the coil, the install tool, the thread tap etc.

I know I could also repair this by just replacing the head. But I'm making a video out of it so I really want to use a repair kit rather than a replacement head.
Click to expand...
Many times when removing spark plugs from customer engines, I find the plugs to be too loose. I think they are afraid of stripping it. Anyway, I have two engines with stripped spark plug threads and one engine with stripped carburetor bolt threads I will work on this winter. Occasionally people call about spark plug thread repair, but I don’t offer this option. Helicoil is a popular brand and holds up.


#5

l008com

l008com

I've only used a helicoil once on an MTB brake caliper and it works really good. The only issue was that it was really hard to keep the tap perpendicular to the hole I was trying to thread. But I did get it eventually, thankfully. These carbon fiber frames are not cheap! But the way spark plug taps work, it should be even easier to do it right.

Now necessary is the thread sealer though? Wouldn't the kits come with it if it was really necessary?


#6

R

Rivets

I always use Lotite blue on any threadsert I install,


#7

l008com

l008com

Isn't loctite just going to burn off after a few minutes of running the motor?


#8

R

Rivets

I’ve never had an insert come loose in my 50 years of experience.


#9

H

Honest Abe

spark plug helicoil repair kit

Home Page - Runnings

www.runnings.com www.runnings.com


#10

StarTech

StarTech

Honest Abe said:
spark plug helicoil repair kit

Home Page - Runnings

www.runnings.com www.runnings.com
Click to expand...
Well those are hard to get started and causes a loose fitting. They are supposed to self feed but don't. I recently tried one on the Poulan with a strip plug hole. Almost never got it started and then kept wobbling around.

It is best to use a regular Heli Coil but those kits are expensive. And mainly only shops can justify the costs.


#11

woodstover

woodstover

When we had our VW aircooled shop we used tons of helicoils for spark plugs/exhaust studs. Always a success. Used red loctite when installing. As a shop, we would buy starter kits for what was required and then just ordered extra inserts kits as required. Slowly built up to having all the common thread sizes. A few seldom used sizes we would buy a longer insert refills and just cut them to length instead of buying different lenghth refill kits.


#12

StarTech

StarTech

That is the problem that cheap kit is not a Heli-coil version but is a threaded insert. Plus they are reaming the hole and then tapping it for the insert all in one operation. Next time I try the kit I brought I am going just drill the hole and they tapping it. But I am looking for regular Heli-coil tool sets for the 10, 12, and 14mm plugs. I know three different kits so that is around $400 to start with.


#13

R

Rivets

Have you seen this kit, had one in the last shop I worked in, before i retired. For M14 I used spark plug tool. https://www.vevor.com/home-tool-kit...MIpbm_3Y_6kAMV7lR_AB0u8Ra5EAQYCSABEgKZavD_BwE


#14

StarTech

StarTech

Not even the right thread pitch.

I need M10-1.00, M12-1.25 and M14-1.25.


#15

sgkent

sgkent

thread cert is more common in the air cooled world. The best fix is to make a video on replacing the head, or show someone how to properly remove the head, weld it, surface, and drill / tap a new plug hole. I would only use a heli-coil or thread cert on a head that was NLA used or new, or very expensive. Lots of the old mower engines from the 1990's are out there in masse as to used parts. Both thread certs and heli-coils can fail or be problematic when the plugs comes the next time the it is removed. So ask yourself why go thru all the hoops to remove and then repair it, then put the old one back when you could have a replacement ready to go.


#16

R

Rivets

What about these individual kits?

E-Z Lok E-Z Coil Thread Repair Kit for Metal - Standard - M10-1.0 x 3/8 SK50932 | Zoro

Order E-Z Lok E-Z Coil Thread Repair Kit for Metal - Standard - M10-1.0 x 3/8, SK50932 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.
www.zoro.com www.zoro.com

E-Z Lok E-Z Coil Thread Repair Kit for Metal - Economy - M12-1.25 x .500 EK51034 | Zoro

Order E-Z Lok E-Z Coil Thread Repair Kit for Metal - Economy - M12-1.25 x .500, EK51034 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.
www.zoro.com www.zoro.com

E-Z Lok E-Z Coil Thread Repair Kit for Metal - Standard - M14-1.25 x 3/8 SK51132 | Zoro

Order E-Z Lok E-Z Coil Thread Repair Kit for Metal - Standard - M14-1.25 x 3/8, SK51132 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.
www.zoro.com www.zoro.com


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