Have you checked for gas in the carburetor after it stops ? Remove the air cleaner and look inside the carb, then move throttle linkage. Is there any gas coming from the accelerator pump? Have you checked fuel pump pushrod for wear?
YNGVE, any good condensor that will hook up will work.
When it stops do you get out straight away and test to see if you still have spark?
Have you actually put a guage on your fuel pump or tested its delivery volume?
