Small Engines (Lawn Mowers, etc.)/cross thread spark plug


Quentin wrote at 2014-12-14 01:35:44
Go ahead and install a Heli-coil. It's not difficult, but if you don't want to remove the head, here's what I've done:before you do the work, make sure the piston is at top dead center. Do not turn the crankshaft once you start the repair. Position the engine so the cylinder is vertical. When you're finished, dip a six inch length of clothesline rope halfway into clean oil. Then fish it carefully through the spark plug hole and slowly, patiently mop up any shavings that may have dropped onto the top of the piston. Sounds dumb, but it works for me. Fixed a Ford Taurus this way.

fred wrote at 2015-01-25 02:06:29
ALL Helli coil kits come with the correct tap. you need the correct drill size to suit, the kit tells you the size required.

as the spark plug must seat properly to compress the spark  plug washer, the drill must be aligned to the original hole.

as for the shavings, and the small tang that is used to screw in the helli coil,which has to be broken off after install of said coil, well thats another worry, take the head off and use the coil, far more durable than alloy.  

ScoutBoy wrote at 2015-02-06 20:58:10
there is 1 critical factor with heli coil. when you drill the hole out to suit the heli, [size is specified on your kit] the drill must aline with the original hole, or the sealing washer will not function properly.

if the seal is the tapered type. change the head.. imo..

good luck..  

Small Engines (Lawn Mowers, etc.)

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Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

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