Spark plug question

jess_monster /

When the porcelain on the spark plug turns brown what does that mean? i.e. too rich/lean cold/hot. Thanks.

Re: Spark plug question

XBrandon EdgeX /

Do you mean the porcealin that's inside the combustion chamber or the porcealin outside? If it's brown on the Inside it means that it's running correctly, but if it's brown after idling for awhile then you should do a "plug chop" (run it at or near top speed and shut the engine down at top speed and remove plug) A plug chop is the real only accurate way to make sure your mixture is right. Black means it's rich and white means it's too lean A golden brown is preffered, but slightly rich doesn't hurt. If it's lean, the engine could seize.

Re: Spark plug question

Ron Brown /


If, as Brandon sugests, the porcelain on the outside of your plug turns brown, I would sugest riding more slowly or wearing depends. : )

For the plug chop he sugests, kill the engine with the kill switch while leaving the throttle wide open, or you will get a bad reading.


Re: Spark plug question

jess_monster /

That's it, forgot to put the depends on today. But seriously, Thanks guys.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account