Last January I had my motor rebuilt. Went with 10.75/1 pistions, new valves and guides.

Ran it all summer and had no issues. Just took it out for a day trip after having the bike sit for 5 months. It was pinging really bad when climbing hard or hitting 5th gear in a drag race. I am running super unleaded. Got any ideas guys?? I think it might be that the gas got old in my tank

 

i'd just add high test and fuel stabilizer. ,pinging useually mean's running hot , to me , check spark plug's , changing wouldn't hurt, clean your carb if it doesn't get better after running new gas in it. are you sure it isn't a rod or piston slapping , one mans ping is another mans rattle?