I know this is one of those "dumb" questions, but can someone explain what jetting is, how it effects the motor, carb etc, and how difficult it is to do.

I am taking a guess, but does jetting involve inlarging the carb parts ?

Sorry for the "hookt on fonix" question, but I gotta learn somehow [img]i/expressions/face-icon-small-blush.gif[/img]

 

Jetting is very involved but basic jetting is enlarging or down sizing the fuel jet or jets in your carbeurator to obtain the best ignition temperature in you cylinder for optimum horse power.
when ever you increase air flow do to engine mods such as air filter or pipe you lean out your air fuel mixture that is being itroduced into the cylinder resulting in a lean air fuel mixture. If the lean condition is to lean it can result in a catistrofic engine failure so to prevent this and get the horse power out of the modifications you installed you would jet it up by installing bigger fuel jets this would compensate for the increase in air flow and produce more horse power.
Hope this helps.