On the way home, she stopped altogether three times. I could see that the fuel filters were dry so there was no doubt it was fuel starvation. My guess is that when the bike heats up, the rubber fuel hoses soften and then close up where they bend. I think it is both the vacuum pipe to the rear of the fuel tap and one or both of the fuel hoses to the carbs. Each time, after the bike had cooled I could see fuel flow into the filters again and so could do some more miles.
So last night I took it all apart again to take out the fuel filters so the hoses would have an easier route to the carbs. And in doing so I managed to snap one of the t-pieces I'd plumbed in to link the two sides of the system!!! So I had to pull the carbs out too so I could remove the broken stub etc.
Ironically, I could see that the carb throats and inlet rubbers were wet with fuel. It is ironic bearing in mind the problem I was trying to solve was not having enough fuel. That suggests I set the float heights too generously. So I'll be adjusting them by 1 - 2 mm whilst I'm at it.
On the plus side, with the carbs out I could do something else. And so I have a nice new heavy duty lead from the starter solenoid to the starter motor ;-)
