Me and my son took the carbs of my 1972/3 Honda CB350 apart to replace the O-ring seal to the float bowl and top of carb. It seemed to go well. But upon trying to start, it would start but would not throttle up. it would die. After several attempts the bike would not even start up. I would appreciate any insight into what may be wrong.                                    Thanks Tony

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1972/3 Honda CB350