Sparkplug Blowing Out of the Hole

[proper]

Just replaced the battery on my 1650 Hydro (Duracell U1R, 12V, 300CCA, 370 CA) Almost finished cutting grass when the tractor backfired (loud with a little black smoke). Try to restart, but it wouldn't turn over. Raised the hood and the sparkplug was out of the hole. Sparkplug was still in the cap hanging by the wire. Screwed it back in, put the cap/wire back on the sparkplug. Try to restart, but it wouldn't turn over. On the second try, it backfired and blew the sparkplug out of the hole again.

Does it sound like the sparkplug is not sitting in properly (worn threads)? Can a sparkplug work itself loose? Could replacing the old battery have something to do with it? The old battery was 9 years old and I kept a maintainer on it. Worked fine until it finally died.

I plan on replacing the sparkplug tomorrow, but I wanted to know if this has ever happened to anyone else? I've never seen a sparkplug blow out of it's hole before. The engine is the original 16Hp Kohler and I don't want damage it.

Thank you.

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[Greg Riutzel]

You'll need another head or install a threaded insert in the hole. I just did this in May with my 1650 and I'm pretty happy with a good insert.

 

[mfrade]

Yep, I'd agree. threads in the head have failed, 2 choices, replace the head (hope you get a good one!) or install an inset to replace the missed / damaged threads. Someone recently had a discussion going on this very topic! Try searching the threads ?!?!? Or look here. Stripped!

 

[proper]

Is this common problem that occurs with age or a misuse?

 

[Greg Riutzel]

Someone recently had a discussion

I think it was me in "Stripped". Follow my posts as I got excellent results taking advice and getting the best product

 

[mfrade]

Is this common problem that occurs with age or a misuse?

It happens.. some due to age and some due to owners over tightening, cue that old adage.. tight is tight, to tight is broke! Steel plug threads against aluminum cyl. head.. it all adds up. Personally I think the insert repair is your best bet. If you get a used head, you won't have any idea how good the threads are. My point oh two anyways! LOL

 

[proper]

We shall find out tomorrow. In my case, the insert repair is probably the best case. The tractor is only used 4 or 5 times a year to cut grass then it is put into storage.

A couple of years back I had to replace the cylinder head due to a hairline crack, probably due heat. I took me several months to find a used aluminum cylinder head in great shape. It wasn't cheap either.

Thanks all.

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[PACub100]

Just watched this the other night...

 

[mgonitzke]

Save yourself 15 minutes and skip to 13:45 in the video... Basically any of the thread insert repairs will be as strong or stronger than the original threads.

 

[jpaulus]

I ALWAYS use never seize on spark plug threads. In any engine I work on ALWAYS

 

[charles germer]

just use one of the spark plug thread solid inserts, for spark plugs only do not use a helicoil

 

[dgeary]

just use one of the spark plug thread solid inserts, for spark plugs only do not use a helicoil

I agree with Charles. I've had to do this repair several times on automotive aluminum heads. You need an insert with a flange on the top similar to the Timesert shown in the video. This allows the insert to be "locked" in place and keeps it from threading through. A helicoil needs a blind hole or will end up threading through when installing the plug.
You can typically purchase a spark plug repair kit from your local automotive store.

 

[mgwin]

Just a thought........... Is there any chance the wrong spark plug was used? All plugs are not the same size diameter at the threads.

Be careful using anti seize on a bolt or nut that has to be torqued. It will "slick it up," and the bolt will have to be tightened up considerably more to get to the torque rating. Did this on some lug nuts once, and ruined the metal rim. Never did get the lug nuts tight enough to make the torque wrench "click."

 

[Greg Riutzel]

Good points but I think you will see a distinct difference between a 12mm that will fall through to an 18mm that won't fit; 14mm being the correct one.

As to never seize or any other slickum, tightening torque should always be reduced, usually 15-20%, and still achieve the spec'd clamp load. Most torque values are based on overcoming thread friction in clean dry or oiled threads. Reducing the friction will need reducing the torque to prevent over torquing and still get the required clamp load. I go with torque angle for the plugs and a bit of slickum as recommended by the plug maker. As shown on the box they come in, the gasketed ones we use get a 3/4 to 2/3 turn after the gasket makes contact between the plug and head. Used plugs, such pulling one for inspection, get maybe a 1/16 to 1/8 turn for the same tightness and only when the head is slightly warm to cool.

 

[mfrade]

Never seize is not a lubricant. It does use an oil to help "Carry" the material , usually copper for high temp use or aluminum for normal uses. The material used is to prevent corrosion between two parent materials and allow release of a fastener. But it should never be considered a lubricant! It is used in static state fasteners. It is not intended for dynamic situations.

 

[Greg Riutzel]

You need an insert with a flange on the top similar to the Timesert

True enough. As I posted above, Heli-Coil has several product lines and the one I used was basically a Timesert knock off, a flanged solid insert for spark plugs. It worked great. However 2 things to keep in mind which I addressed in the "Stripped" thread are modifying the tool end a tad as the hole is over the intake valve on a K341 I assume the OP has in his 1650; and make sure to give the sealant/adhesive a full 24 hour cure.

 

[charles germer]

I agree with Charles. I've had to do this repair several times on automotive aluminum heads. You need an insert with a flange on the top similar to the Timesert shown in the video. This allows the insert to be "locked" in place and keeps it from threading through. A helicoil needs a blind hole or will end up threading through when installing the plug.
You can typically purchase a spark plug repair kit from your local automotive store.

agree on the reasons not to use a helicoil on a spark plug, they do make a kit called save a thread. that most would use due to it's easy on ones wallet price, personally i have had them come back out when the plug is next changed. yet still it is preferable over the coiled SS type
work wise i do a lot of auto head repairing, i use both timesert + TIME-SERT® SPARK PLUG THREAD REPAIR KITS + spark plug stripped thread repair kits for spark plug problems, thread stripped spark plug repairs in damaged threads in spark plug hole stripped out approved thread repair, aluminum head spark plug repair and locknstitch Spark Plug Hole Thread Inserts On Lock-N-Stitch both have a double oversize for when a 1st repair fails again

 

[Ray Shotwell]

Never seize is not a lubricant. It does use an oil to help "Carry" the material , usually copper for high temp use or aluminum for normal uses. The material used is to prevent corrosion between two parent materials and allow release of a fastener. But it should never be considered a lubricant! It is used in static state fasteners. It is not intended for dynamic situations.

Nickel anti seize is rated to 2600 degrees I believe.

 

[mgonitzke]

Never seize is not a lubricant. It does use an oil to help "Carry" the material , usually copper for high temp use or aluminum for normal uses. The material used is to prevent corrosion between two parent materials and allow release of a fastener. But it should never be considered a lubricant! It is used in static state fasteners. It is not intended for dynamic situations.

One should consider it a lubricant in the context of torquing fasteners, though.

 

[Ed Rollins Jr]

Believe it or not this just happened to my old Cub Cadet last weekend! 18 HP Kohler engine, this info is really super! Thanks!!!