I down jetted to a 68... and have tried NGK B6HS, B7HS and b*hs plugs - STILL having problems. I have been told from a local moped rider, "hesitation" is the wrong term... I'm "bogging down" I have removed the air filter, and drained all the fuel tonight (in case I got some bad gas, or some asshole put something in my tank) and will refill tomorrow. I will probably get a new fuel filter as well. I was running perfect for weeks... now I can't go a few blocks with out problems! This is a completely rebuilt E50 - new bearings and seals, new crank - everything! I hope some of you Old Skool cats can help me trouble shoot this!!