Bike will run well on a cold start. Idle down well for about 5 minutes, them starts to falter and will stop if you don't tickle float.Then it will run smooth again for a few minutes then repeat problem. Tried reving motor with throttle and it will back fire as if running lean. Have flushed tank, checked gad cocks, fuel lines all clear. Pulled carb apart 6 times perfectly clean. Valve clearance is correct, point gap correst seems to run out of gas and I can't find anything wrong with fuel system. Any Ideas out there?
Thanks in advance, Brent

email (option): bgblakkely@shaw.ca

It sounds obvious but is the breather in the filler cap clear ? It is only a small opening. Have you tried running with the cap open ?

You could try running with the float chamber cap removed to get an idea of what's happening. Is the top of the float needle free in the boss in the cap ?

Yes I have left cap open, I'll try running with float top off. Seems real odd as it has run like a top for the last 4000 miles. Thanks for your response, Brent

email (option): bgblakkely@shaw.ca

Should mention that I have another M20 running that I switched complete float assembly with and still runs out of gas and stops.

email (option): bgblakkely@shaw.ca

Another silly question! Are you sure you have enough head of petrol in the tank? I had exactly this problem with my Speedtwin. I did all the things you have. Looked in tank, yes it looked like enough fuel. But with the bike on rear stand there wasn't enough to keep the carb full for long. After about a fortnight of farting around..... All it need was another 1/2 gallon. Ron

email (option): ronpier@talk21.com

Have you taken the fuel line of the carb then turned on the taps to check fuel flow, I had a (friend) whom after farting around for two weeks was reminded about the strainer on top of the taps in the tank
Mick

email (option): michael@nammech.com.au

That doesn't sound like you, Ron !

The Norton can do odd things too, bearing in mind there that the two halves of the tank are divided high up. The point about the height of the rear stand is also very valid, with the taps well to the back of the tank.

As people have said, check the fuel is coming out without obstruction. I would put the bike on the stand, undo the pipe and let it flow into a container. If it's not a good flow, clear it with a small drill bit.
But if you have fuel coming out when you tickle it, it sounds like you have a flow. It could be that it IS running lean. Does it help if you put the choke on after it starts to falter? Do you have the right size jets?
If that's all ok the only thing I can think of to do if try another carb.

email (option): horror@blueyonder.co.uk