Running issue 1979 kz650

I took my kz650 out today for the first time, it ran and rode very well then I took it on the interstate, hit 5th gear doing about 65, then I started hearing what seemed (through my full face helmet) like a highish pitched hum and it stopped accelerating, then when I got to my off ramp and down shifted it died. When I restarted it it would start and then if I gave it throttle it would make an odd sound and die. Eventually got it going then got almost to my destination and it did the same thing this time I was doing town speeds (35mph) then later we tried riding it to a mc mechanic and it died halfway there and took 20 mins to start butnit wouldnt ride. When we pulled the plug it was dry but there was fuel in all the bowls

Does it have oil in it? Riding hard when it made the noise?

It has oil and I wasnt running it hard

Maybe do a compression test. Also try taking the RH ignition cover off and turn the motor over by hand, see if it feels smooth and does not make similar type noises. Could also pull the oil filter and look for signs of metal in it, drain the oil too and look there.

I took it to a mc mechanic and he mentioned cam chain guides

Devin7717 wrote: I took my kz650 out today for the first time, it ran and rode very well then I took it on the interstate, hit 5th gear doing about 65, then I started hearing what seemed (through my full face helmet) like a highish pitched hum and it stopped accelerating, then when I got to my off ramp and down shifted it died. When I restarted it it would start and then if I gave it throttle it would make an odd sound and die. Eventually got it going then got almost to my destination and it did the same thing this time I was doing town speeds (35mph) then later we tried riding it to a mc mechanic and it died halfway there and took 20 mins to start butnit wouldnt ride. When we pulled the plug it was dry but there was fuel in all the bowls

Try running with the fuel cap cracked loose.
Bill

Make sure the battery is good --- test it with a digital multimeter. Even if new, check it.
If a wet cell battery, make sure the electrolyte levels are correct --- only add distilled water if necessary.

Check the ignition coils for cracks or damage. If original, they may need replacing. A simple check is to ride the bike at highway speeds if possible, then stop & feel the coils, press hard with your fingers --- they should be warm, not hot. Hot indicates internal shorts or something.

I got the call from the mechanic yesterday. It was just bad vacuum. The diaphram had been taken apart and reassembled wrong, as a result I wasnt getting fuel.