Stripped Spark plug

[krosemond]

I think I may have made a bad mistake. In my ongoing effort to get fire to one plug, when I was reinstalling the plug, I stripped the threads in the engine and the plug won't tighten. Is there a fix that does not involve replacing the head?<br /><br />Depressed in NC.

 

[Little Bear]

Re: Stripped Spark plug

Maybe a Helicoil kit will save you on this one. They work well in some automotive situation. They are availible almost everywhere. <br />Best of Luck,<br />Little Bear

 

[12Footer]

Re: Stripped Spark plug

A helicoil will work

 

[JB]

Re: Stripped Spark plug

Hey, krosemond. I agree that a helicoil will work and save you big bux. There is another product that would work even better if you can find it. I bought some from Clark's Corvair parts house when I was restoring a Corvair Engine for installation in a VW bus. It was an aluminum sleeve that screwed in in a similar way to helicoils, but was thermodynamically compatible with the aluminum heads. Because of the thermodynamics it allowed plugs to operate at the same temps as though there was no modification. Sometimes helicoil installed plugs get hotter than in a stock operation. That could affect performance and reliability. The risk is small, and if helicoils are what you can get by all means use them.<br /><br />Bon Voyage.<br />JB

 

[krosemond]

Re: Stripped Spark plug

Thanks guys. I really felt kinda stupid doing that, but it sounds like it may be a common mistake, if not just an unfortunate occurrance. One thing that concerns me. Will it leave any trash in the cylinder? Can I vac-key-ume it out before re-installing the plug?

 

[JB]

Re: Stripped Spark plug

Take the head off to do the fix.<br />Good Luck<br />JB

 

[Little Bear]

Re: Stripped Spark plug

Krosemond,<br />Get an old speaker magnet (donut shaped) and set it over the hole. When you drill the metal ,if it is ferrous steel will stick to the magnet.<br />Good Luck,<br />Little Bear

 

[ODDD1]

Re: Stripped Spark plug

Krosemond, Helicoil makes a specific insert for repairing stripped plug holes...is called a KEENSERT....a one piece steel insert...you retap the hole larger an install this piece,i use em all the time for guys that get too excited changing their plugs....can be done with the head in place...just gotta be careful.

 

[krosemond]

Re: Stripped Spark plug

Thanks ODDD1, I must admit, I was so excited to get the plug sparkin' I got a little too aggressive putting it back in. Could have been the brew. Anyway, where can I find a KEENSERT? Does it require special tools for reaming the hole before inserting. Also, I was told that you could fill the cylinder with gillette foamy and then vac key ume it out with a shop vac and the shavings will come with the cream. Any opinion on that trick?

 

[ODDD1]

Re: Stripped Spark plug

yes special tool needed...[as usual]..i always greased the tap an took my time....factor in the cost/time pulling the head an patience comes easy

 

[krosemond]

Re: Stripped Spark plug

I tried a fix that you guys may not approve of, but I figured it was worth a shot, although I kind of dread the "cussing out" that i am probably gonna get here. I spread a thin layer of JB Weld ( a product that I have had great success with in many applications) on the threads of the plug and tightened it right to the point where it was giving before. Ater setting for 24 hours, the plug was stable. I fired up and she ran well, spraying soapy water around the base of the plug and it showed no compression leak. I took her to 4000 rpms and still the plug is stable.<br /><br />I know this is not a permanent fix, but if it holds, then I will pull the head off in the fall and fix it right. I am not a mechanic, I am a boater, and although it is not always the best thing to do, I look for the fix that will get me home. Or back on the water in this case. Let me know if I am being too foolish, it is a case of risk vs return management.

 

[wesal1]

Re: Stripped Spark plug

I hope you have better luck than I do using MR. J.B. WELD. The last time I let it set up, it was impossible to free the item. Looks like you are going to be taking the head to a machine shop in the fall.<br /><br />? what if the plug flows out sometime this summer?

 

[krosemond]

Re: Stripped Spark plug

I thought about that. I left enough of a oily film on the plug, and only wiped the inside of the hole with a paper towel, thinking that would enable me to break it free. I guess we will see in the fall, or if the plug fouls sooner. It was admittedly short sighted thinking. Kind of like day trading, sometimes you win big, sometimes you lose your pants....

 

[ODDD1]

Re: Stripped Spark plug

Krosemond, i give you credit for being an effective butcher...LOL.....when the goal is to get her up an runnin guys like you always shine.....no matter what happens remember, it was junk when you started....

 

[boatmotor]

Re: Stripped Spark plug

Hi krosemond Just the other day a buddy<br />stripped the plug threads on a eighteen<br />Evinude. Just put new gasket on motor.<br />No problem to remoe head took it to Merc.<br />shop installed a helicoil for $10.00<br />Regards Tom

 

[krosemond]

Re: Stripped Spark plug

ODDD1, thanks for the kind words. With six kids and a 50+ hour a week job, the objective is to use her when I can, and let guys who know how to do it right, fix it while I can't use her. I love to tinker, but admittedly, I don't really know what I am doing. I was the kid who took apart his bike and then asked Mom to take it to the shop in a bag full of parts to get it reassembled. But that didn't stop me, and eventually I could put it back together. Thanks in part to you guys, and the "school of hard knocks", I will get this outboarding thing down. My first boat was a diesel inboard. I never had to worry about the engine, only the support systems. But I've got some great stories about getting home "against all odds" using available resources.<br /><br />Well, I am pulling it down to the coast this weekend, so if you don't get an update on Tuesday, call the coast guard.<br /><br />Have a great holiday weekend.

 

[dougb]

Re: Stripped Spark plug

Why not try to make some kind of clamp or brachet similar to the OMC Ficht Fuel injector bracket? Just kidding krosemond, but you are scaring me! You didn't mention what kind of motor this is, but I cannot believe that it is not worth fixing correctly, two wrongs don't make a right. What happens when the plug blows out, still connected to the plug lead sparking at 30,000 volts and a precise mixture of fuel and air is blowing out of the hole and into the cowling. I may be all the way out here in California, but I don't want to read about you next week.

 

[Little Bear]

Re: Stripped Spark plug

Yeah, watch out Krosemond you might have created an outboard a-bomb, or you might be struck by lightning! or the moon might fall on you! just kidding.<br />Little Bear

 

[SeaBear]

Re: Stripped Spark plug

I'm with Little Bear here [we bears must stick together!] - we hope your plugs not welded in but you must score points for effort? ... mmmm and with 6 kids you are prone to repeatable conditions so get it sorted when the weather turns nasty and try not to blow yourself up but my take on that is that we can get a little TOO scared of petrol/air mixtures? Give me petrol any day over LPG or hot diesel ... but do be careful?

 

[SeaBear]

Re: Stripped Spark plug

I feel I have to quickly add something to that before I get plastered with replies? Over here in the UK we are being forced due to petrol prices [brace yourselves - currently £0.78/litre!!! [that's at a roadside station, on the water it's nearer £1!! Anyway, we are being forced to consider diesel [for boats it is £0.30/litre] or LPG [£0.28/litre] but to convert my SB Chevy [Volvo] V8's will cost lots and the downside arguments are considering pressurised tanks of LPG, I have seen a small butane gas cylinder destroy a boat in seconds. I have heard that hot diesel is equally lethal because it 'explodes' hence the noise diesels make! But petrol is in the 'burns rapidly' category - it still gets f.hot and will singe all your body hair and ruin Calvin Klein undies but will probably only launch your engine hatches into the air and not demolish the boat - so I'm told? Now you can abuse me ...