Cross threaded spark plug hole

[Guest]

Yeah, don't know how or when, but was fogging today, went to but the plug back in and it just wouldn't go, backed it off, looked at it and the threads look damaged. What the heck do I do???

[ebijack]

get a spk plug tap (M14 i believe). with all the plugs out (just makes it easier) put that cyl at top dead center. coat the tap with vasaline and easily thread it in. the vasaline will pick up 90% of any chips. use shop air to blow out anything that might have dropped in. rotate to bottom dead center and blow out again, then back to top dead center just to be sure.. since your there :) . and ALWAYS use an old sparkplug boot to start your plugs!!! you'll never strip one again. a piece of 3/8 hose works also but not as good for me.

[perchjerker]

do what ebi said but an old trick is to fill the cylinder with shaving cream by squirting it in the plug hole after the piston is at tdc. this stops chips from falling in the cylinder and gives the motor a nice, freshly shaved smell

;)

[Tim_Kelly]

I would have thought shaving cream, being a detergent, would be a bad thing to squirt in the cylinder as it could break down the engine oil if you don't get it all out again?

[perchjerker]

its such a small amount it wont matter. and its very mild, it doesnt harm your skin does it?

motor oil has detergent in it too

[DonnGolden]

the tool you really want to use is a form tap, M14X1.5 metric tap. A form tap
is designed to make the thread by forming the material around the tap. It
produces no chips therefore eliminates the chips in the cylinder problem. Simply
turn it in the damaged tread and it will fix any cross thread you have. Use a
heavy duy cutting oil though, I recomend vaseline for babies butts, but not
threading cylinder heads.

[ebijack]

form taps are not available everywhere. they are ment strickly for production applications. (same type application for making bolts.. roll forming). and quality cutting oil is only needed when actually drilling/tapping. to clean up a stripped hole, cutting fluid is not needed since hardly any material will be removed if any depending on how stripped it is. and if you don't like vasaline you can use 100% silicone grease. BUT! vasaline will not affect any sensors that might come in contact with used/burnt vasaline where silicone can damage sensors. and vasaline is oil based... petrolium.
but i'm no expert, and i do use vasaline for other applications than a baby's butt.

[staylor]

I also bought a spark plug rethreading tap many years ago from the JC Whitney auto parts catalog that works very, very well and is very similar in performance to a form tap. After rethreading and carefully wiping out any left over chips with a cotton swab I go to the "secret weapons"- a shop vac followed by a piece of chewing gum, slightly used, stuck on the end of a number 2 pencil or a small diameter dowel. I learned this trick back in '65 doing a conversion to 4 downdraft carbs on a Chevy Corvair. The conversion kit had you drilling holes straight down into the intake manifold for the extra 2 carbs, followed by the shop vac and the chewing gum on a stick. I've used this trick ever since.
Doug