What was I thinkig?

[phatdaddy]

looks good, i worked in a lawn mower repair shop and we put in hundreds of those. we called them heli-coil kits.

[THEFERMANATOR]

Originally Posted by phatdaddy

looks good, i worked in a lawn mower repair shop and we put in hundreds of those. we called them heli-coil kits.

What he used is called a timesert, heli-coils are the wound up wire ones whereas the timesert is a solid inserert.

[phatdaddy]

thats what i get for being on the computer without 2x reading glasses. heli-coils look like springs, i see now they are a solid piece, almost like a threaded bushing. these actually look a little more substantial, although we never had a helicoil fail, anyway, a lot cheaper than new heads.

[RWilson2526]

Nice repair.....thats one of those things where you first think holy crap am I screwed or what?....and then it occurs to you that you cant possibly be the only guy in the world to do it and somebody has already figured out how to fix it relatively easily.

[nymack66]

Thanks Guys, It was quite an experience for me ...

[Destroyer]

Heli-coils have a special tap that has slightly elongated threads. The heli-coil itself is like a spring...it's not solid. After you thread the hole you screw the heli-coil onto a special inserter tool. When you insert the coil into the newly threaded hole the slight streach of the coil then mimics the regular tpi of the bolt hole. You have to use a special inserter (comes with the kit) to insert the heli-coil, and after it's inserted you have to use a hammer and punch to break off the inserter tang at the bottom of the thread. I've used them on hundreds of different sized holes in my day, but truthfully never did a spark plug hole with them. 5/16x18, 3/8x16 and 1/4x20 are the most common sizes used. They work well on bolts that are not removed on a regular basis.

The problem with heli-coils is that they tend to loosen up or come out with bolts that are removed over and over, so they aren't the best bet for spark plug holes where you remove the spark plug on a normal maintenance basis. For holes like that I highly recommend genuine time-serts (www.timesert.com) because they do several important things. 1) They have a shoulder on the top that provides a positive stop and prevents the insert from threading itself deeper into the hole. and 2) the last few threads of the insert are not fully finished, so that as you screw the insert into the hole the bottom threads expand, and that permanently locks the insert into the head metal.... no locktite is needed. They are a little more expensive, but in my opinion, they are well worth the extra bucks .

[awthacker]

Speaking of dumb moves... I blew my engine up about two weeks ago. Tried to start it, forgetting that the the plugs were out. The fuel under the cowling caught a spark somewhere and BLAMO! Lesson learned there. The explosion separated one of the latches from the cowling (which was easily epoxied back), blowing it halfway open and starting a small fire that burned on the fuel and oil in the motor housing until extinguished. I then learned that the extinguisher on the boat had no charge and had to dash for another in the garage. Overall no damage. Just some burnt wire sleeves. The only real bummer was that some fire extinguisher discharge made it into the open cylinders. I blew them out with compressed air and cleaned it the best I could. I'm hoping that didn't or won't cause any harm.

[Destroyer]

Originally Posted by awthacker

Speaking of dumb moves... I blew my engine up about two weeks ago. Tried to start it, forgetting that the the plugs were out. The fuel under the cowling caught a spark somewhere and BLAMO! Lesson learned there. The explosion separated one of the latches from the cowling (which was easily epoxied back), blowing it halfway open and starting a small fire that burned on the fuel and oil in the motor housing until extinguished. I then learned that the extinguisher on the boat had no charge and had to dash for another in the garage. Overall no damage. Just some burnt wire sleeves. The only real bummer was that some fire extinguisher discharge made it into the open cylinders. I blew them out with compressed air and cleaned it the best I could. I'm hoping that didn't or won't cause any harm.

Which is exactly why you carry a Co2 extinguisher onboard your boat. No residue to clean up. I'm sorry you had the fire. Lesson learned as they say.

Because ot the EPA, tree huggers and global warming BS you can no longer buy them, but if you can find them the absolute best extinguisher to have is a Halon unit. Safe, effective and zero residue. Next best is the Co2 units, but not as safe in a confined space since the carbon dioxide displaces oxygen. Lastly is the good old dry powder that you used.. good, effective but makes a mess to cleanup afterwards.