I just cleaned the carbs,jets and floats and refitted. I can get the bike running using a temporary fuel supply and the air box off. Curiously, fuel comes up the cylinder head breather and sprays everywhere! What is going on? I have to say I was using the throttle and the choke to get it started. it doesnt want to idle but sounds fine whilst running. When i fit the air box and tank, it won't start. all advice welcome.

Vacume pipe

Have you refitted the fuel tap vacume pipe?

It turns out that fuel had been gathering in the oil sump due to a float valve having been stuck prior to the recent carb overhaul. I dumped the oil and all the fuel and that was the end of the issue. Its running lovely now. Starts first time, which was the purpose of the excercise. I wonder if something catastrophic would have happened?

thebugser wrote:I wonder if something catastrophic would have happened?

Yeah, the fuel will breakdown the oil and then it offers zero protection to your engine. Presuming it hasn't been able to get to that point then you can breathe a big sigh of relief!