[Filip75]

I keep on hearing these terms, but I have no idea of what's involved in the procedure.

Could someone please clarify?

P.S. I did a search and didn't find anything useful :dunno

 

[The Finn1]

this is the 101 explanation

Jetting is related to carburators and mapping to fuel injection. Rejetting means changing the carburator jets (different sizes) so that the amount of fuel is optimal with the amount of air directed to the engine. jet too big= runs rich. jets too small= runs lean (depends on other things too but to give you the simple pic)

Mapping means the same thing only done with a computer "map"/program that directs the fuel injection.

Both are often needed when the exhaust and intake air mods have been done.