i was out on my 81 Yamaha xj650 , when it started acting funny , loss of power , sputtering ect , seemed VERY hot , letting her cool down for awhile and ill check it later , pulled the plugs and all 4 are burning normal , not wet and oily , anything else i should check ? thanks

Oil level ?

just checked it , was a little low , bike is cool now and was checking for loose connections , still running funny , almost like a backfire out the right exhaust

Sorry i'm not familiar with the specific bike, Has something come loose, check exhaust connections, is the exhaust corroded and blowing anywhere ? is it a points ignition system, maybe new point and capacitor (condenser) are needed, also check ignition timing.

waited a few hrs and checked everything again , oil was very low , added some and let her cool down and everything seems to be back to normal , good idle and the sound is strong again , i used to work on my little 150cc scooter , and traded it for the bike , 08 scoot for a 81 bike lol , cant go wrong , the bike seems to be built like a tank , thanks 4 the help

Keep a check on the oil level

turns out it was the petcock valve , was screwing with it today and put it to prime , so the valve or the vacuum line is shot , works great on the prime position