GSXR 400 stops after .5 hr
I have a 1985 GSXR 400 GK71F that is hard to start, but when started runs for about .5 hr then stops. After about 10 mins cooling down it starts again, runs for about 10 min then stops. Ive replaced the CDI and regulator, frozen the pickups with a can of freeze which didnt seem to help. Spark is very weak when it wont start, but is a lot stronger when it does start. There is always fuel in the bowls. Wiring looks ok. Runs well when its running. Any ideas on this piece of history?