Went from best way to paint to 2 vs. 4 stroke.
Well to get back on topic, here's what I would do:
Take the engine out of the bike (if it's in there).
Take the covers off (clutch, crank, and generator) and remove the gaskets. Also take off your exhaust and gasket.
Spray the covers with Auto strip or Aircraft remover. Then spray the engine with the same stuff. This will remove the gray paint or whatever is on the chengines. Let the stuff get dry and flakey. Have a beer, or chill out for a while.
When it's dry and flakey, hit every part with a drill and wire wheel to knock off the flakes. Anything else sand off or respray. After this is done, take a damp cloth and wipe everything you sprayed thoughoughly.
Go to an auto parts store or wallyworld and buy engine paint with ceramic. This is fuel and heat resistant. You don't necessarily have to primer the stuff but it may help. There's no need for clear coat unless you want it.
When you spray the parts, hold the rattle can about 4-6" away from the part and do several light even coats. Let each coat dry, have a beer or chill out or whatever, and do all over again and again until it is all covered.
Put everthing back together.
If you want to do some custom stuff. Then after the parts are stripped, take a sharpie and draw your design on your covers or whatever, then use masking tape to tape off the section you don't want, let's say black. Then spray the whole part black, the same way I stated above.
When that's good and dry, remove the tape and then tape over the sections you painted black. Spray the new section with red or blue or whatever. Repeat the same process as above. When that's dry remove the tape and lightly sand the borders to help erase the lines, then you could get some adhesive pin striping to cover the border, or paint the pin striping on. If you use the adhesive type, then spray everything with a couple coats of clear.
Everything can be done with rattle can. If you want to use conventional spray paint, be sure to primer and cover with automotive clear, because grease, gas, and heat could and will damage your paint job.