hey thanks for the clarification and info re beam adjustment ... i will check it out now if someone can give some teeth to valve adjustment on the 300 that would be fine......
re is it big enough fast enough (can i ride two up),,,,,can i really tour/cruse with it etc. this is all "up in the air" as i would say...and depends on what floats your boat!......anyone trying to punch out 90 mph on the 300 (must weigh about 125 lbs) or has seriously modified it etc....is clearly ....flirting with the devil....that's just me talking...i am very conservative ...and haven't gone over 65.....on mine ....you can do some two up riding if your companion is a light weight ..i guess...but as others have stated you probably need to move up to a 400 cc at some point,,,,
as for substitutability(if there is such a word)....a car is a car and a bike is a bike....you probably need to get a cheap cage.....good luck