180cc running then overheating and dying.

[dazza1974]

Hi all, I've just put in a new 180cc bore kit into my old 125 direct bikes Scooter. I had trouble yesterday getting it started and after a lot of head scratching figured out I'd timed it up wrong. So, I get the bike running today only for it to shut off after about a minute or 2 of running. It starts up lovely and runs real nice, sounding lovely with an aftermarket exhaust on it. You can just hear a slight misfire every now and then but it will suddenly become tappetty almost and starts knocking then dies. I'm thinking it may be overheating due to the timing being out slightly.....am I right?