is loctite suitable to replace stripped threads on block

[sprouticus]

OK.......so my friend and I replaced the spark plugs on my 1977 70 hp evinrude.(almost $40 for 3 plugs.ouch!!) anyway, my friend took out the old plugs while I was working on something else. he said all plugs were torqued tight, but none more so than any other. When he took out the bottom plug, he noiced metal shavings on it. Upon examing the hole where the plug goes, we noticed there was almost no threads left there. We tried screwing the plug in anyway, but as soon as we started the engine up.the plug shot out. I called up my local dealer, and explained that I knew you could tap out the block, and screw in an insert that would then allow me to screw in the plugs, but I told him I was hoping there was a cheaper and easier solution. (I had just bought the boat, and had already over-extended my budget on it, so didn't want to pay for shop time. Also I felt this job was too delicate for me to do and not screw up.) Anyway, he told me "no problem", I could buy some loctite for a few dollars that would solve my problem, and that he knew many backyard mechanics that used loctite on their cars when this happened. I came to the conclusion that this is what the previous owner did, as I do not think you could cross thread a plug by removing it. So we bought the loctite, put in the plug, waited for it to dry, and when we cranked over the motor, the plug shot out again. However on the second try it held, and I have been using it now for about a week with no obvious problems. I've had approx 3 hours at WOT, and 7 hours at slow idle. My question is, how permament is this solution. I know the clyinder is firing because when it is running, and I pull the plug wire, I can hear the RPMS go down. should I just leave it, until the next time I replace the plugs???<br /><br />thankyou for taking the time to read this post, and offering your advice

 

[cvx35]

Re: is loctite suitable to replace stripped threads on block

LOL, Do what you want. You could probably make it back to the ramp on 2 cylinders if you give it enough throttle.<br /> Here's a suggestion: Get a cylinderhead gasket from your dealer. Around $20 maybe. Also get a small can of gasket sealer at the dealership. You remove the cylinderhead yourself. Take it to a backyard mechanic, welder etc... Let them tap it and install a helicoil. You might even pick that up at the dealership.<br /> For dangsure don't do all that with the cylinderhead on the motor. Metal shavings ain't good. You might have 60 or 70 bux invested? Oh i forgot gas prices and all that runnin' around you'll be doing. 160 or 10 bux invested.<br /> Good luck. Oh I almost forgot. Don't take the watercover off of the cylinderhead.

 

[RPJS]

Re: is loctite suitable to replace stripped threads on block

Hi<br /><br />The simple answer is that this plug is going to come out again.<br />Loctite is used to hold good threads fast not to repair/ replace damaged threads.<br />I would recomend that you get the repair done A.S.A.P, phone around a few auto shops, they should have the tools required to do the job.

 

[wcraige12]

Re: is loctite suitable to replace stripped threads on block

just wanted to say, thanks for the chukle. and if you continue to rely on the locktite please keep us posted on what happens.

 

[hvacman]

Re: is loctite suitable to replace stripped threads on block

lol i know a guy that used epoxy on his, works great till you have to remove it

 

[McGR]

Re: is loctite suitable to replace stripped threads on block

I agree with everyone... forget the loctite, fix it properly with a repaired/replacement head or insert. Also, I hate to kick you when you're down but $40 for three (Q)L77JC4 plugs is outrageous. I never pay more than $2.50 each for these. Next time try somehwere else for your plugs. Most marinas, auto parts stores and even discount stores carry this plug.

 

[Dhadley]

Re: is loctite suitable to replace stripped threads on block

#1 -- what in the world did you buy with those 3 plugs for $40? Even a large pizza wouldnt kick it up that high....oh! The beer that goes with the large pizza. Gotcha!<br /><br />#2 -- Think about this, youre riding along at whatever rpm - doesnt matter. Pop! out comes the spark plug. Now its still hooked to the plug wire. And the motors running. So the plug is firing (it better for $13 a piece!!!). And gas is now being sprayed into the small confined area under the hood.<br /><br />Take a video. I want to know how high that hood will actually go.

 

[rodbolt]

Re: is loctite suitable to replace stripped threads on block

thats a good engineering question <br />how many revolutions would it take for one cylinder to fill the volumetric space under the hood with enough vapors to ignite

 

[jim dozier]

Re: is loctite suitable to replace stripped threads on block

For about what you paid for the diamond encrusted spark plugs you could have bought and installed a helicoil insert yourself. Oh I forgot about the head gasket. Add another $15, and the job would be done right.

 

[cvx35]

Re: is loctite suitable to replace stripped threads on block

Dang, I'd not take all that verbal abbuse! :/

 

[cvx35]

Re: is loctite suitable to replace stripped threads on block

Must of been stainless steel plugs.

 

[sprouticus]

Re: is loctite suitable to replace stripped threads on block

LMAO@ALL OF YOU............Dhadley, your scenerio woke me up, I have already found someone to fix it for me. For the record, the spark plugs were BPZ8HS made by NGK, and after taxes came to $38 and change Canadian (about $30 american). They don't carry that plug at Wallmart or the auto parts store I usually go to, so I tried the marina next. I'm used to paying like $2-3 each for my bike and sled so that seemed like a lot. Anyway, thanx for the chuckle at my own expense, you opened my eyes.

 

[kesso]

Re: is loctite suitable to replace stripped threads on block

--------<br />Product:<br />LOCTITE 480 Toughened Instant Adhesive<br /><br />Properties:<br />*High Impact, high peel and shear strength toughened cyanoacrylate adhesive.<br />*Bonds metal, most rubbers and plastic, etc..<br />*Fast fixturing time of 10 to 20 seconds<br />*Temp. range -55 deg.C to + 100 deg.C<br />*Shear strength - nom. 26N/mm(sq) (3,770psi)<br /><br />Functions:<br />*Can replace welding and riveting in many applications.<br />*Particularly suited for bonding metal to metal, metal to rubber and metal to plastic.<br />------<br /><br />Go for it! I just want to see if the advertising is true or a load of BS!

 

[RPJS]

Re: is loctite suitable to replace stripped threads on block

originaly posted by kesso<br /> --------<br />Product:<br />LOCTITE 480 Toughened Instant Adhesive<br /><br />Properties:<br />*High Impact, high peel and shear strength toughened cyanoacrylate adhesive.<br />*Bonds metal, most rubbers and plastic, etc..<br />*Fast fixturing time of 10 to 20 seconds<br />*Temp. range -55 deg.C to + 100 deg.C<br />*Shear strength - nom. 26N/mm(sq) (3,770psi)<br /><br />Functions:<br />*Can replace welding and riveting in many applications.<br />*Particularly suited for bonding metal to metal, metal to rubber and metal to plastic.<br />------<br /><br />Go for it! I just want to see if the advertising is true or a load of BS! <br />

Hey kesso<br />If this stuff does what it says on the tin we can all throw our spanners away and just glue everything back together again, it'll make for a much lighter tool box

 

[dragula65000]

Re: is loctite suitable to replace stripped threads on block

To be perfectly honest, this is the dumbest thing I've ever heard. I dont mean to knock you down, but seriously. About the outrageous price for the plugs, I've been boned too, so I won't comment. But Locktite? If you really wanted to redneck it, then use JB Weld. Locktite is specificaly used to hold a fastener at a specified torque in extreme vibrating environments. I work on aircraft and use it all the time. The best way to fix it is the right way. Pull the head, and use the RIGHT size drill bit to clean up the old threads. Get a helicoil kit or equivelent, and use the proper helicoil tool to install it. If not, you can cross thread it and then start the process over with a larger helicoil. All tha coil does is imbed itself in the metal, and you can use the same size plug. Just putting new threads in pretty much. Or you can possibly tap it, but you may upsize the hole. All in all, take your time, be patient, and try not to screw it up. Its an expensive job, and if you majorly fubar it, Take it to someone else, and bite the bullet. REmember, use Locktite the way its supposed to..

 

[rodbolt]

Re: is loctite suitable to replace stripped threads on block

sprouticus<br /> if worse comes to worse I think I have a few of those heads in my scrap pile. I cleaned out some sheds the other day and tossed all kinds of blocks and heads out back. most the blocks have rust on the cyl now due to a windstorm damaging the roof a few months ago. lost 25 cranks, 30 or 40 rods and 7 or 8 blocks of various makes. so I got mad and tossed them all out in a pile

 

[Dhadley]

Re: is loctite suitable to replace stripped threads on block

Now thats the best (correct) solution yet.<br /><br />And when you get the head, get rid of the incorrect plugs and get Champions in there before we have to start looking up piston numbers.

 

[sprouticus]

Re: is loctite suitable to replace stripped threads on block

champions???........it's been my experience with my dirt bike and sled that champion are the cheap wall mart plugs, NGK is the better sparking, more reliable plug. NGK's were on the boat when I bought it, so thats what I replaced it with.

 

[ob15]

Re: is loctite suitable to replace stripped threads on block

Champions should be the only plugs used to run an OMC.

 

[Flak]

Re: is loctite suitable to replace stripped threads on block

Umm, Loctite is a brand, not a product. The Loctite 480 mentioned above is in fact an adhesive, not a thread locking compound. <br />Sounds like a pretty wicked adhesive too.<br /><br />I wouldn't want to test it on a plug though, go with the helicoil.