87 Gas EZGO Spark plug pops out of engine

[thetexasdeb]

I have an 87 EZGO Textron gas buggie. Lately, the spark plug comes out while driving and although I replaced it with a new one I can not seem to get it to tighten completely and it pops out. Any idea how to fix the problem? That plug was an NGK6 but I just found the manual (thanks to this site) and I purchased an NGK5. Could that have been the problem or are the threads stripped?

[CP241]

You’ll probably have to replace the head. You may be able to get a time sert kit and repair the spark plug threads if you can’t find a head

[wicked872]

you will have to use a spark thread repair kit commonly called a heli-coil available at auto parts stores, the best way is to remove the head because the process makes shavings, I have greased the tap before using which held most of the shavings. Good Luck

[thetexasdeb]

Thanks for the replies. I will try to get someone to pull the head off for me.
Does that mean it will take a different size spark plug?

[meimk]

No, the idea of the heli-coil is that the hole gets enlarged and an insert goes inside that enlarged hole with threads to match the original spark plug.

[slonomo]

Thread insert kit should solve the problem. With aluminum heads people often overtighten the spark plugs and strip the threads, very common. Shouldn't put a ton of effort into "torque" when installing spark plugs. "Just tight" is what Grandpap always said.