Aircooled wont run on petrol Help needed

[crazydiamond]

Im at my wits end so need  help.
My 1982 CU 2lire Aircooled runs perfectly on LPG, but a litle time ago tried petrol and it wont run at all. So I thought, start from tank as follows:
1. new Bosch fuel filter by tank
2. new updated fuel pipe all through to take E10 fuel
3. new electric fuel pump
What has this acheived, well fuel pumps all the way upto the carbs but stops there. The float chambers are not filling although the valves above the float are working perfectly. there is power at the elecric choke circuit but I dont know if all the solonoids are working. Could this be the problem? there is a solonoid on the left hand carb on the end of the cross engine vaccum pipe that meters the left carb from the right carb I think, should this click when ignition is turned on or what? What is causing the no fuel problem? I tried filling both fuel float chambers and the engine started and ran well untill the fuel had been used. Then it stopped.

What can I check and how? I only have a Hayes manual which is hopeless with the carbs.

[crazydiamond]

?

[Rosie n' Jim]

I think the first thing to do is to get fuel flowing into the float chambers. If you already have fuel at the carb input, but no further, the float valve is probably blocked. Could be gum left by evaporated fuel or rubber debris from old fuel pipe breaking down. I had the latter issue on one of mine.
​​​​​​Blowing into the input pipe is likely to force the blockage deeper into the valve. I think you'll have to get the top off the carbs and clean the valves. 
It's a bit fiddly to open them up, but you can check the float bowl and main jet whilst you're at it.