I think you should check for diagnostic codes, as described above, to be safe.
then....it depends on the "knocking noise".
- if it ceases the instant you turn off the ignition, it's a rod knock.
- if you still hear a tap, tap, tap after cutting the ignition, while the flywheels are winding down, it's a valve train noise.
a valve train noise could easily be caused by a lack of oil, loss of oil pump suction, or water in the oil. water in the oi is a common winter problem. people start and run their engines without riding he bike and allowing the oil to get over 200 degrees.....or they go for short rides, not allowing the oil to get over 200 degrees. the result is, condensation collects in the oil. if your oil is a tan color....that's water and you should change the oil before ridding the bike again. if it's due, you should change the oil. if you are guilty of any of the bad winter behaviors, change the oil.
I prefer Royal Purple, Max Cycle 20w-50 synthetic oil. it's very expensive and worth every cent. it is the only oil I use in my bikes. you can order it from Amazon.
let me know if you need more help.
if not, please leave a POSITIVE RATING.