yeah a jet swap is pretty easy, it's a 5 minute job
there's 2 bolts to remove the carby from the manifold,
2 screws hold the bowl to the carby, then undo the Pilot Jet and swap the new one in, then reassemble and feel the difference
there will be a number on the side of your jet on the slotted screwdriver end, so if you have the fuel bowl off for any reason note down that number, and the Main Jet too.
i have 2 spare Pilots Jets here that will suit it, probably have 2 or 3 Main Jets too
just check that the plug says NGK Japan, there are NGK china plugs too.
you can get an Irridium plg for it, a CR7HIX, they are about $18ea, or around $13 ex UK inc post.
i would look at upgrading the Spark Plug Lead, i will try and find you a link for one
and leave the current CDI on it, it should last a while