hey guys i justed joined the site in hopes that someone could help me out. last year i was rewarded with my dads 78 SR-500. its an awesome looking bike, the deal was if i could get it to run then it was mine. long story short it took replacing the battery, a new spark plug, cleaning out the carb and buying a new needle valve to get it to turn over and run. so i once i get it running it was blowing out black smoke. my dad suggested let it run for a while and just in case its needs to get all the old junk out.(it hadnt been started in 10+ years) so i thought it might be old gas so i drain the tank and carb to fill the bike up with some new gas. well its still running like that and if i try to take it out it starts to idle funny and dies. plus it wont rev past 3.5k i believe. whatever suggestions you guys have that could help me out would be appreciated. one of my goals is to get this bike up and running so i can drive it to work this year. i need your help.