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Ka-Pow!


Brent_Baumer

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Mowing along w/ my 916H. Here a rattling sound off and on. Can't figure out the source. Raise the hood while mowing to see if I can find it. Rattle Rattle Ka-Pow. The spark plug comes flying out. Hmmmmm. Blew the threads right out of the head. Vacuumed out the debris. Can't get the plug to tighten back up. Need a new cylinder head at the least. Had trouble with the plug getting loose on it's own before. Shoulda checked it more often. Hope not too much damage. Sucks. Brent
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Brent get a helicoil kit.It consists of an oversize tap and a screwthread insert. Retap the plug hole and screw in the helicoil insert. It should be as good as new. Alot cheaper than a new head. I have done this alot of times on car engines, works every time You gan do it with out removeing the head. After you tap it out turn the engine over with the starter to blow out any fileings. This & $1.00 might get you a small coffee Maynard aka/UCD
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Hi, If you do it on the engine, coat the tap with grease, fill the flutes. This will catch most of the chips. Then with the piston up use an air nozzle with a long tip that will go inside the hole and blow any debreis out. Good luck, Al Eden
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If all else fails, pull the head, have the spark plug hole heliarced shut, drill, & tap new threads. Did that with my B-1 and it worked fine. Whoever is doing the welding has to be careful not to warp the head. Roy
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Two questions. Where do I get a helicoil kit and how do I re-tap the hole on the engine and keep the tap straight up and down? Thanks, Brent
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Hello . Maynards where do find helicoils for spark plugs ? can.t find them in my area . I always have to take them to the shop. Brent I just bought a 917 did the same thing about 5 minutes after I got it home . I took the heads off takes about 5 minutes had helicoils put in both heads the other wasn.t for behind it . I think steel inserts are better than than when the head was new . Good luck, Pops.
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Actually, the inserts I've seen for spark plugs are more like a thin threaded sleeve than a true Heli-coil. I'd think any small engine shop would be able to install one for you. Heli-coils will work, I just wonder how they affect the heat range of the spark plug, not transmitting heat as well as the bare aluminum of the head.[A href='http://www.wheatfarm.com']http://www.wheatfarm.com[/a]
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Your local auto parts store should carry a heli coil repair kit with everything you need, though I would check around some small engine repair shops for a used head. You might be able to get one cheaper than a repair kit. Scott
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I've used helicoil inserts with a lot of success, but I would remove the head from the engine first. If you do it on the engine, you take the chance of leaving metal chips from the tap in the cylinder. They can do a lot of damage to your cyl. walls, piston and rings. You should be able to find them at any auto parts store. Good luck John[A href='http://www.emhart.com/products/helicoil.html']http://www.emhart.com/products/helicoil.html[/a]
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To jlsater: Helicoils or any insert do not affect the heat rance of the plug. The heat range is due primarily to the temperature of the combustion products inside the head. In effect compression ratio, air-fule mixture, etc. Not necessarily the temperature of the head itself. The insert itself is so small compared to the mass of the head that after a few minutes the plug will be at the same temperature regardless of whether the plug connects directly to the aluminum head or the steel insert. By the way, installation of inserts is usually one of the first things done to racecars with aluminum heads. Pit crews don't want jammed or stripped plugs at the track. Rod H. Rod H.
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If you can find a shop that uses timeserts, they are the best repair I've found for aluminum heads, as they are made from a copper alloy that has heat transfer similar to aluminum.
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Brent, You can go to any Pep Boys auto store. They have a kit for replacing the threads. The inserts supplied come in various lengths. At the top of the inserts around the outside edge you will see knurling. This knurling digs into the head so the insert will not loosen when you remove the plug. Everything you need is in the kit. The tool for peening the edge of the insert so the knurling digs in is included. Just make sure the insert is screwed in far enough. The tap is supplied to install the insert. I like to remove the head from the engine. It's safer and easy to do...Woody
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Brent I always got mine at a napa store. Any good parts store that services your local car dealers and auto shops will have them. The tap that comes with the kit is a double size tap. The small end is the same size as the spark plug and threads into those threads the over size part cuts new threads for the helicoil. A tool comes with the kit to install the helicoil. You might want to pick up some thread locker to lock the helicoil. This & $1.00 might get you a small coffee Maynard aka/UCD
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Yeah, timeserts were the type if insert I was thinking about. http://www.timesert.com has info on them.[A href='http://www.wheatfarm.com']http://www.wheatfarm.com[/a]
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A real genius told me today to wrap the spark plug with tin foil (like you would with teflon plumbing tape) and thread it back in. "It will work - guaranteed". Don't think I'll be trying it. Brent
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Brent, now that sounds like something you do to your snowmachine out on the trapline 120 mile from anywhere and its 50 below zero..MPH
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Brent, we use something called keenserts. They are a thread in thread style of inserts. They are far superior to the helicoils. It takes a special kit to install this style of insert. It uses four triangular shaped pins to drive into the aluminum head once the insert is threaded in. Then a special seal ring is pressed in between the insert and the aluminum head. The tool used to drill the head cuts a groovein the aluminum to accomodate the seal ring. Neal
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Brent That is one of those in a pinch fixes. I knew a guy that punched a hole in an oil pan 17 miles back in the woods from main road another 13 miles to town. He cut a maple plug and pluged the oil pan filled it with water and drove out. he replaced the pan, flushed the engine with kereosene filled it with oil and kept running it no problems. this & $1.00 might get you a small coffee Maynard aka/UCD
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