I have a kitted e50. The kit that is on it is an older kit. I think it's about 3 years old and an airsal euro kit. I was running a proma circuit and it would go just under 50mph. I recently switched to a 6p and now it is definately going faster and revving higher but makes a pinging noise at high speeds? The only other thing I have changed is my spark plug. Oh, and I up jetted as well. Does anyone have any ideas as to what could be causing this?