color of spark plug

[NRPkfx400]

The other day i took out my spark plug to put in a new one and noticed that the plug was all black and charred. The previous put an hmf on it but i dont think he rejetted. He gave the HMF main jet that comes with the pipe. Should i put the new jet it and see if it changes the color of the plug? Thanks.

[indyZrider]

if its that dark and sooty then its running rich. you need to lean it out a little

[NRPkfx400]

So should i rejet or just mess with the tuning on the carb?

[cataway]

you only need to be conserend with the porislin part of the plug.
there is nothing wrong with being a little rich ,you'll find your engin will run a little cooler if its a tuch rich.