G’day guys, I'll start from the start I've only been riding for about 6 months now and this is my first bike (2001 VTR250) also I’m not very mechanically minded but I’m getting better, this is also my first post so go easy if sound like a noob because I am . Now I have had some problems with the bike overheating and took it to the mechanic and they replaced the thermostat and the fan switch, I later discovered that the radiator cap was faulty and has been replaced. So after all this I will get to the problem, after riding for about 30 mins most times three quarters of the way to or from work my bike seems to keep overheating though not quite hot enough for the warning light to come on and I get this occasional crackle. It occasionally happens in second but most of the time in third and it only happens when I open up the throttle, but when under steady revs it is gone. The sound itself sounds like popping candy in ether the engine or radiator. If anyone has had this problem or can help that would be much appreciated.