Recently I replaced the fuel filter of my PG1 after almost 38K kilometers and I never seen such black filter my whole life, thankfully the machine still running smooth.
Well one of the reason why I replaced the fuel filter was because recently I noticed that after running or moving for around 60km/h the speed suddenly stopped and even worse getting lower. I thought it was the filter since it was 38K already but I was wrong. The real reason why the bike behaved like that is because of the plug coil, before upgrading to Tuneboss ECU I replaced the plug coil to a performance coil with the brand BRT (I have posted about that in previous entry) and I never thought that would be the cause, maybe the new ECU doesn't responded well with the new setup. So after thinking about it for a while I made a conclusion that if it's not the fuel, it has to be the spark and I replaced back the stock plug coil and luckily the bike comes to normal as before.