could be a rock or mud stuck in somthing,or maybe chain to tight?i had a similar noise on mine then when i gave it a good wash with the gurney it was fine,so prob a rock stock in something maybe?
well it started crackling after i cleaned the bike with the gurney, and it sounds like the crackling is coming from the exhaust, and it only makes the noise when I rev the bike. But the bike is also running rough so i think i might need to adjust the valves. Thanks
pull the carby apart and CLEAN it really well also you might as well remove the fuel tank and swish some fuel around in it and tip it out NOT IN THE DRAIN....then start the bike up with fresh fuel and go for a ride might also pay to check the valves but the carby is the problem for sure its pretty common on small dirty engines