Motorcycle Repair: 1973 engine losses power, wiring harnesses, cb500

Question
I have a 1973 CB500 (mint!) Idles fine and forever, but as soon as I take it out (1/2 mile) rpm's  drop and throttling has no effect. Won't start back up. Pushed it home 4 blocks, got it in the garage and after a few minutes started right up again. I have heard replace ignition coils, retifier, have the stator rewound(?)(F). So my son has the stator pulled out, but it is attached to 2 wiring harnesses and he said he has to CUT one of them to take it in! What do you think I should repair first? FYI-new spk plugs, fuel line, oil. I have a CLYMERS manual, but it doesn't give the specs on OHMS  and resistance for the ignition coils. Any help greatly appreciated!

Answer
Mlle, first thing is to pin down the problem. i have my doubt its ignition. Dont cut anything !!! there isnt anything needed to be cut to take it out. lets pin the problem first. need to get the bike to shut down and carry an extra spark plug with you, even riding up down the driveway if you have to. when the bike shuts down pull a plug wire and check for spark with the other plug. if it doesnt have spark ill run you thru the steps to find the  problem. if it does have spark, open the fuel cap Immediately and listen for a vacuum or hissing sound. wait a few seconds and try to start it, if it starts your tank isnt venting and its just running out of fuel. this is first hand experience with that model i have seen it before. lets try these steps first.

Eric