# Deluxe 28 spark plug problem



## Orange renegade (Aug 16, 2021)

Hi,

I let me friend remove the spark plug on my airens snowblower now he says the new one wont go back on?
Any idea how I can fix this if he ruined the threads? I know the angle is kind of weird.

Thanks !


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## Big Ed (Feb 10, 2013)

Orange renegade said:


> Hi,
> 
> I let me friend remove the spark plug on my airens snowblower now he says the new one wont go back on?
> Any idea how I can fix this if he ruined the threads? I know the angle is kind of weird.
> ...


You must look at it first, see what is wrong.
Did he screw up the new plug or the threads?
You can try to chase the threads with a tool.
But first look.
And take the machine back!


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## tabora (Mar 1, 2017)

Orange renegade said:


> Any idea how I can fix this if he ruined the threads?


If he didn't start the new plug in with his fingers, it's likely he got it in cocked and damaged the threads. You can use a backtap tool to fix them.








14mm Back Tap Thread Repair Tool Auto Repair Tool Threading 640811 SG | eBay


14mm Back Tap Thread Repair Tool 640811. 3/8" Inner Tie Rod Remover Low Profile Turner Removal Install Car Repair Tool SG. Broken Spark Plug Remover Kit Tools 65700 Fit Ford Triton 3V Engine 2004-2010 SG.



www.ebay.com


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## Toon (May 11, 2021)

Lisle also makes a tool and is made in the good old USA. At 13.03 CND it is a good value.
I do like the slender profile of Taboras back tap thread repair tool, but so far I have not had trouble with clearance using the Lisle tool which uses a spark plug wrench socket.


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## tabora (Mar 1, 2017)

Toon said:


> but so far I have not had trouble with clearance using the Lisle tool which uses a spark plug wrench socket.


The advantage of the backtap tool is that it is inserted and expanded into the good threads at the bottom of the spark plug hole, and then cuts/cleans the buggered threads on the way back out.


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## Orange renegade (Aug 16, 2021)

I tried to install the Champion plug he bought and it goes half way and stops, The original was a torch but this one looks the same

Champion rny9c

but I already ordered the tool to help, Thanks so much


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## RIT333 (Feb 6, 2014)

Seems very strange that it will thread 1/2 way, and then stop. Are you threading it in by hand - highly recommended.


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## Orange renegade (Aug 16, 2021)

I tried but it just seems to stop? it does not seem to start well by hand now, But OK if I use the ratchet. Its a tight angle compared to my old toro that was straight \ on top.


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## Oneacer (Jan 3, 2011)

Wow, some people want to change a spark plug every year .... Never seen the reasoning for that.

just about all my machines are running the original plugs, and they start and run just fine.


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## Tseg (Jan 29, 2021)

My 1st two-stage 24” I bought was a cheap Chinese version… $350 new with a knock off Honda engine… I gave it away after 12 years when it started to need more than 1 pull to start and bought myself a real Honda. I changed the oil annually but never pulled the plug. After 12 years a lot of things were starting to rust and the engine leaked oil slightly. In summary, 11 years probably would have been a good time to change plugs. My Honda engined mower that gets a lot more hours of service annually needed a plug change after 8 years… was starting to need 2 pulls to start first time ever. After the plug change, like brand new again and 1-pull starts.


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## UNDERTAKER (Dec 30, 2013)

*Put a new head on it and send him the bill.*


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## Yanmar Ronin (Jan 31, 2015)

A good macro/close-up picture of what you've got might be a big help here.


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## deezlfan (Nov 8, 2017)

*SLOW DOWN KEYBOARD COWBOYS!!* First we have to figure out whether this is the correct plug. A Champion rny9c ? Never heard of that number and I've been selling Champion plugs for 45 years. If the OP gave some model number info that could be checked before he starts trying to 'fix' a problem he may not have.

We also neglected to tell him about what is needed to use that tool correctly so he doesn't fill his cylinder with metal shavings if his threads are messed up.


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## Yanmar Ronin (Jan 31, 2015)

deezlfan said:


> SLOW DOWN KEYBOARD COWBOYS!!


Yee-haw... 🤠 That's why we need pictures. 👍


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## Orange renegade (Aug 16, 2021)

I mistyped the spark plug number rn9yc is what the box says - I do not change it every year, this is the first since I bought the machine in 2018 so I figured it was time- I will get some good pictures this evening. Thanks all for the help


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## Zavie (Sep 23, 2014)

Probably a typo. Champion RNY9C is common.


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## Yanmar Ronin (Jan 31, 2015)

Orange renegade said:


> I let me friend remove the spark plug...





Orange renegade said:


> I bought the machine in 2018 so I figured it was time...


These two statements concern me the most here. 

Why did you have your friend mess with the engine, and what is his (her) experience with small engine repair?

And why did you 'figure it was time"? Was the machine running poorly in any way?

Looking forward to the pictures... hopefully it hasn't been damaged for no good reason. 🤞

🍻


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## Orange renegade (Aug 16, 2021)

Yanmar Ronin said:


> These two statements concern me the most here.
> 
> Why did you have your friend mess with the engine, and what is his (her) experience with small engine repair?
> 
> ...


Yeah- It was running fine but he said five years was to long, I told him to never mind but he did it when I was on vacation with the family... He was watching my dogs so I know he meant well.
but with winter coming, not the best time for sure. I ordered the tool so it should arrive soon- I will give it a go ! I did not tell him anything as I kind of want him to stay away from my stuff.


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## Oneacer (Jan 3, 2011)

Too late now, but there was no need to change out that plug .... Those are aluminum heads vs a steel threaded plug ... can easily mess up the machine if one does not know what they're doing.


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## Orange renegade (Aug 16, 2021)

That is for sure ! Aluminum seems a bit to fragile but I am sure has some benefits..


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## Oneacer (Jan 3, 2011)

Aluminum heads will dissipate heat faster. This allows for higher Compression Ratios with less risk of Detonation. The cooler head also delivers a cooler air/fuel mixture to the combustion chamber. Cooler air is denser and can make more power.


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## Big Ed (Feb 10, 2013)

deezlfan said:


> *SLOW DOWN KEYBOARD COWBOYS!!* First we have to figure out whether this is the correct plug. A Champion rny9c ? Never heard of that number and I've been selling Champion plugs for 45 years. If the OP gave some model number info that could be checked before he starts trying to 'fix' a problem he may not have.
> 
> We also neglected to tell him about what is needed to use that tool correctly so he doesn't fill his cylinder with metal shavings if his threads are messed up.


Curious? Tell me.
Besides taking the head off how would you keep the shavings from dropping in the cylinder?
Grease the tool and spark plug hole? But first stuff a rag down into the hole?
I never had to do a chase on a spark plug hole.


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## BazookaJoe (Oct 6, 2019)

deezlfan said:


> *SLOW DOWN KEYBOARD COWBOYS!!* First we have to figure out whether this is the correct plug. A Champion rny9c ? Never heard of that number and I've been selling Champion plugs for 45 years. If the OP gave some model number info that could be checked before he starts trying to 'fix' a problem he may not have.
> 
> We also neglected to tell him about what is needed to use that tool correctly so he doesn't fill his cylinder with metal shavings if his threads are messed up.


I have one of that Champion part number in my garage.


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## deezlfan (Nov 8, 2017)

Yes, grease and a cautious clean-up.


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## deezlfan (Nov 8, 2017)

I'm thinking you truly don't have a MY9C plug in your garage, because it was a typo.

Also the M at the beginning of a Champion plug part number would indicate a shielded design intended for use around military ordinance. Y is an invalid shell designation.


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## BazookaJoe (Oct 6, 2019)

He has an RN9YC spark plug. Capital letters are important for clarity, hence engineering drawings are typically always all caps.


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## tabora (Mar 1, 2017)

deezlfan said:


> A Champion rny9c ? Never heard of that number and I've been selling Champion plugs for 45 years.


Google even figured it out instantly... Just a typo.
_Including results for Champion *rn9yc*_​_Search only for Champion rny9c _​​


deezlfan said:


> We also neglected to tell him about what is needed to use that tool correctly so he doesn't fill his cylinder with metal shavings if his threads are messed up.


Grease on the backtap and then compressed air with the exhaust valve open.


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## Zavie (Sep 23, 2014)

Orange renegade said:


> I will get some good pictures this evening. Thanks all for the help


Pics???


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## Zavie (Sep 23, 2014)

While we wait for the OP's pics I'll share my picture of the threads on my Sthil MS-251


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## Orange renegade (Aug 16, 2021)

Sorry I was working 24hr shifts and I fell asleep- I will get these


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## Orange renegade (Aug 16, 2021)

Here is a picture of what I have.


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## Oneacer (Jan 3, 2011)

Ouch ... ^&$%^%@$


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## Orange renegade (Aug 16, 2021)

yep figured the same. I might have to send it in to a small engine repair guy vs me who might make it worse


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## Zavie (Sep 23, 2014)

Wow, that's terrible. Do you think you can pull the head yourself?


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## Big Ed (Feb 10, 2013)

Orange renegade said:


> Here is a picture of what I have.


You should have told him to use a wrench not a HAMMER. 
Can you focus the camera some? Maybe your picture is making it look worse then it is?


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## ChrisJ (Nov 27, 2014)

Is everyone else seeing something I'm not?

I see a picture that looks like it came from a flip phone with very little detail. I can't really make out how bad it is or isn't there.


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## Zavie (Sep 23, 2014)

Good enough on my screen to see it's not right. Better resolution would help determine what options are available


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## ChrisJ (Nov 27, 2014)

Zavie said:


> Good enough on my screen to see it's not right. Better resolution would help determine what options are available


Your picture looks fantastic.
The one the op posted isn't useable to diagnose and help to in my opinion.

I can't tell what's not right about it. It looks boogered up early on, but I can't tell for sure and my eyes are pretty good.

I think one thing that's bothering me is if someone wasn't able to remove and install a spark plug I've got a feeling repairing a spark plug hole, or replacing a head is out of the question.
I don't mean that in an insulting or disrespectful way at all.


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## Zavie (Sep 23, 2014)

The OP didn't pull the sparkplug. A friend did it for him without his permission. We don't know the OP's skills except that he did say he is leaning towards taking it in for repair. I think that is a good idea.


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## captainrob1 (Dec 16, 2018)

Orange renegade said:


> Hi,
> 
> I let me friend remove the spark plug on my airens snowblower now he says the new one wont go back on?
> Any idea how I can fix this if he ruined the threads? I know the angle is kind of weird.
> ...


There is a tool called a “BackTap”. I used on my Pressure Washer that repaired the threads as you back out this tool with grease on the end which captures the filings as new threads are made…..need the right size Back Tap for that sparkplug hole…


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## captainrob1 (Dec 16, 2018)

captainrob1 said:


> There is a tool called a “BackTap”. I used on my Pressure Washer that repaired the threads as you back out this tool with grease on the end which captures the filings as new threads are made…..need the right size Back Tap for that sparkplug hole…


I ordered mine online….NAPA makes one too…nifty tool …the “BackTap”


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## WrenchIt (Dec 6, 2020)

captainrob1 said:


> I ordered mine online….NAPA makes one too…nifty tool …the “BackTap”


The Back Tap was mentioned and discussed earlier in this thread.

History tends to repeat itself.


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## Yanmar Ronin (Jan 31, 2015)

If this "friend" of yours is any kind of friend at all, he will pay for a new head and installation.

/IMO


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## WrenchIt (Dec 6, 2020)

I will add something here. I mow my front lawn every week with my lawn tractor - a 1 acre lot minus the house, drive, walkways, etc. The back gets mowed every 2nd or 3red week. I usually put 25-35 hours on the hour meter each year. My snowblower gets even less of a workout but say it gets 25 hours each year. The manual for my tractor says change the oil every 50 hours or annually. I forget what Honda says since I change the oil every spring before storing it for the summer.

Five years and 125 hours is hardly enough to break in a spark plug. With that kind of usage, you can easily go 10 years or longer. 

When you replace a plug, put it in the spark plug socket, attach a short extension to the socket, (NO WRENCH) and thread it in by hand. index finger and thumb only.. The socket wrench is used to snug it up. Choke up on the handle so the pad below your index finger is over the center of the ratchet wrench and tighten to make the plug snug - you don't want to strip out the threads. If you grab the wrench's handle its too easy to apply too much torque and over tighten the plug.

My snowblowers have a spark plug recessed in the housing/shroud of the snow blower, requiring an extension on the plug socket. If yours has the plug sitting proud on top of the bare cylinder head, skip the socket and thread the plug in by hand all the way. Then snug it up with the socket and wrench.


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## JJG723 (Mar 7, 2015)

When working with delicate threads like this, instead of immediately trying to screw in the plug, first slowly turn the plug in reverse. You will be able to feel the threads drop into place. Now you should easily be able to screw in the plug by hand until it bottoms out and then snug up with the wrench/ratchet.


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## chipg1956 (Mar 28, 2021)

.


tabora said:


> If he didn't start the new plug in with his fingers, it's likely he got it in cocked and damaged the threads. You can use a backtap tool to fix them.
> 
> 
> 
> ...


This tool works great and I have used it to repair many machines. It does require care in using it. Read the directions. In my experience you probably have some sort of China clone, copy of a Honda. Often times, due to questionable quality control, a build up of tolerances can occur where the spark plug wrench will bind up on the valve cover. Trying to screw it in with a sprk plug socket attached is NOT a good idea with these motors. To make sure this never happens again, after repair, replace the 13/16 spark plug with one with a hex size of 5/8. I use the Autolite 3924. Certainly nothing would be wrong with using the platinum or iridium version of the same plug. The China motors come in lots of different names but if your machine doesn't say Briggs, Tecumseh or Honda you can be pretty sure it is from China. Now all of you that love these things please don't jump all over me. These cheap motors are a pretty good value for the price.


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## Orange renegade (Aug 16, 2021)

I am not sure why the picture came out so bad, My Iphone is not all that old ! but it seems my buddy has a problem with spark plugs - I learned he just did the same thing to his Mom's lawn mower !
So why is this ! Well I had to ask, turns out he has a new air compressor he was excited to use and he used an impact tool to place them back in- this explains it ! Dummy

After this I said this is your fault, this is stupid and you are going to pay for the repair. This morning the guy picked up my snowblower and it will be repaired the right way. On a plus side he noticed my friction disc is worn away by the tab on the side. The machine is five years old so I get this covered as well for my troubles.

I will let you know what the repair guy says and what ends up happening . I want to Thank everyone who took the time to respond to my help request, Seriously this is a great group.


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## Oneacer (Jan 3, 2011)

Air gun on a spark plug install into an aluminum head ..... now that is one I never heard of before .... 

Needless to say, your buddy is not the brightest person, maybe even some learning disabilities ...


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## Yanmar Ronin (Jan 31, 2015)

This tale is turning into an episode of the Twilight Zone.


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## BazookaJoe (Oct 6, 2019)

I've often thought that there are people who absolutely should not be allowed to own tools. The OP's buddy is EXACTLY one of those people!


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## Orange renegade (Aug 16, 2021)

LOL ! I almost died when I found out, I would of never guessed this in a million years- While he is very good at his job as a lawyer, fixing things is just not for him !


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## Orange renegade (Aug 16, 2021)

BazookaJoe said:


> I've often thought that there are people who absolutely should not be allowed to own tools. The OP's buddy is EXACTLY one of those people!


100% - He should not own any tools at all, ever...


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## Yanmar Ronin (Jan 31, 2015)

Orange renegade said:


> LOL ! I almost died when I found out, I would of never guessed this in a million years- While he is very good at his job as a lawyer, fixing things is just not for him !


How is his sense of smell?


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## Orange renegade (Aug 16, 2021)

The smell of destroyed aluminum ! So he it taking his Mom's lawn mower to the same repair place. I think he is done at this point. In the end, it all worked out- It will be 70+ degrees this weekend so it will be good until my machine makes its return trip home. I will let you know the totals when I know them and what was done just so the thread can end properly.


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## Oneacer (Jan 3, 2011)

I am sure they will take off the head and inspect the damage, and either put on a new head or possibly clean it up and insert a Heli-coil or other type of insert.

Your buddy might want to consider retiring himself from doing repairs. Not only costly for him but could get someone hurt.


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## michaelnel (Feb 12, 2019)

Spark plugs can sieze from dissimilar metal corrosion. I usually wipe some nickel anti-sieze on the plug threads (don't get it on the electrodes or insulator, just the threads) before carefully screwing it in at least one turn by hand.


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## WrenchIt (Dec 6, 2020)

Oneacer said:


> Needless to say, your buddy is not the brightest person, maybe even some learning disabilities ...


No need to bad mouth the guy. Give him credit for stepping up and correcting his mistake. I've had a lot of successful, smart doctors and lawyers as customers over the years, and more than a few have done some pretty dumb (mechanically speaking) things. Ever hear a lawyer discussing how stupid your average burglar is? Does it make sense to get a speeding ticket in the same town on the same street more than once? Do Docs berate you for delaying treatment for what was a simple cut and is now infected?

Most of us have made dumb mistakes, its how we learn.


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## crazzywolfie (Jun 2, 2014)

michaelnel said:


> Spark plugs can sieze from dissimilar metal corrosion.


i could be wrong but i think this is not usually much of an issue because of the coatings used on new plugs. it shouldn't need anti seize but never hurts


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## WrenchIt (Dec 6, 2020)

michaelnel said:


> Spark plugs can sieze from dissimilar metal corrosion. I usually wipe some nickel anti-sieze on the plug threads (don't get it on the electrodes or insulator, just the threads) before carefully screwing it in at least one turn by hand.


If you anti seize threads, decrease torque by 15 to 20%. Use only two fingers instead of three to snug it up.😆


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## Oneacer (Jan 3, 2011)

"Most of us have made dumb mistakes, its how we learn."

A dumb mistake is one thing ... taking an impact air gun to install a spark plug into an aluminum small engine head is way beyond a mistake, that is sheer stupidity.


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## Big Ed (Feb 10, 2013)

I guess an air gun is better then a hammer. 
I wonder why he bought an air gun?


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## tabora (Mar 1, 2017)

Big Ed said:


> I guess an air gun is better then a hammer.


Not if he had it set for a zillion ft-lbs... That just makes it a thread stripper.


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## Tony-chicago (Feb 10, 2021)

Wow. Okay he does not know and has little experience. When you have a hammer....

Every thing I have to fasten, I do backwards by hand. Everything. From lightbulbs to...

As stated earlier, feel for the threads to drop in place then forward. This is especially true for cars and other expensive items. Most common, spark plugs. To use an air wrench. Well okay. Course they can be useful. And if he sells it to you...
This wil be a minor issue and easily fixed. Just like stated above. Pricey, but not a disaster.

Have you ever stripped the heads on a classic Ferrari.


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## Orange renegade (Aug 16, 2021)

The repair guy just called and said it is a mess, New head is required at this point. Not sure about anything else yet


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## michaelnel (Feb 12, 2019)

crazzywolfie said:


> i could be wrong but i think this is not usually much of an issue because of the coatings used on new plugs. it shouldn't need anti seize but never hurts


Likely true, but I started working on stuff back in the early 1960s and it was a good practice then. Won't hurt now though.


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## michaelnel (Feb 12, 2019)

WrenchIt said:


> If you anti seize threads, decrease torque by 15 to 20%. Use only two fingers instead of three to snug it up.😆


I agree, torque specs are for clean dry threads. That said, I never use a torque wrench on spark plugs. I feel for when the crush washer has been crushed.


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## tabora (Mar 1, 2017)

This is my hand position for tightening spark plugs (with or without extensions as needed). I haven't stripped one since the 1970s...


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## WrenchIt (Dec 6, 2020)

tabora said:


> This is my hand position for tightening spark plugs (with or without extensions as needed). I haven't stripped one since the 1970s...
> View attachment 201146


Exactly as I had described. 

I hope none of you guys ever make a mistake... @Oneacer - I'd hate to have you for a teacher.


Orange renegade said:


> The repair guy just called and said it is a mess, New head is required at this point. Not sure about anything else yet


I must admit, I'm surprised at this, but I have not seen the head. I thought Helicoil's were magic and would fix just about everything...but have limited experience with them.


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## crazzywolfie (Jun 2, 2014)

WrenchIt said:


> I must admit, I'm surprised at this, but I have not seen the head. I thought Helicoil's were magic and would fix just about everything...but have limited experience with them.


some shops won't do it that way because they can't guarantee that it will last. a return customer from a failed repair costs them more.


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## ChrisJ (Nov 27, 2014)

Oneacer said:


> "Most of us have made dumb mistakes, its how we learn."
> 
> A dumb mistake is one thing ... taking an impact air gun to install a spark plug into an aluminum small engine head is way beyond a mistake, that is sheer stupidity.


If he pays for it I'll give him a pass

Admitting you messed up and making it right is a huge thing and very hard to find


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## tabora (Mar 1, 2017)

WrenchIt said:


> Exactly as I had described.


Yeah, I've said it a bunch, too. I do the same thing with a 10mm socket on a 1/4" drive 5" handle for shear bolts. Figured it was time for a picture.


WrenchIt said:


> I must admit, I'm surprised at this, but I have not seen the head. I thought Helicoil's were magic and would fix just about everything...but have limited experience with them.


I have not used Helicoils, but have had good experience with full inserts, as long as the cement holding the insert cures well.


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## JJG723 (Mar 7, 2015)

Helicoils serve 3 purposes.

1. Repair stripped out threads.
2. Add durability. For example, where a screw/bolt will be repeatedly put in and out.
3. Add strength. When the torque spec of a screw/bolt is greater than the capacity of the threads that it is being screwed into.


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## Yanmar Ronin (Jan 31, 2015)

Regardless of personal opinion(s), let's keep the public crucifixions to a kinder, gentler dull roar... something something SBF high road.

🍻


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## Toon (May 11, 2021)

Usually when threads strip out of a hole aside from cross threading is because the bolt being used was too short and there wasn't enough thread length to carry the torque. The thread charts say that 3 full threads are enough to handle full torque on a rated thread diameter. I like to see double the bolt diameter at least, but that likely comes from my phase of fastening dies to bolster plates on presses. Vibration isn't kind to threads. In my experience Helicoils are a last resort used to repair an expensive item and they usually fail over time, but I must admit I have never sealed them in with cement. The kits I used never had it. 
Another drawback is that the Helicoil introduces a second point of resistance to the spark plug current circuit going to ground. In my opinion they have their uses (they save money on part replacement), but I try to avoid having to use them. The proper thread length and proper torquing practices mentioned above are a much better way forward.


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## Orange renegade (Aug 16, 2021)

The machine is back ! All in all not bad, Around 200 for a new plug, oil change, drive disc change and spark plug hole fix. While it is still warm here, you never know


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## jr27236 (Feb 19, 2021)

tabora said:


> If he didn't start the new plug in with his fingers, it's likely he got it in cocked and damaged the threads. You can use a backtap tool to fix them.
> 
> 
> 
> ...


One tool I have NEVER seen. That is in genius!! Thanks for the link Tabora


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## Sam Am I (Oct 28, 2021)

jr27236 said:


> One tool I have NEVER seen. That is in genius!! Thanks for the link Tabora


Ditto........I hope I never need one, but the guy who made this certainly was thinking outside the box, it so makes very logical sense too!!....Geeesh.


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