Carb problems!!!!

[Arni]

Hi, can anyone help
I'm working on a bus with 34 Pict 03 carb, it starts on choke but I noticed the fuel air cut off wasn't screwed in tight and the wires to the choke unit and valve weren't connected to the positive side of the coil. I've tested the cut off valve and it works fine but as soon as you connect the wire to the coil it cuts the engine out when running and will not start from cold.
Has anyone got any idea of what to next???

 

[purpledog07]

hi, sounds like the fuel cut-off solenoid is faulty. there should be no way to start the engine while the solenoid is fitted but not connected. when connected to pos side of coil it should be open and as soon as voltage is removed the solenoid should shut off the fuel supply inside the carb. small cable - 0.5 to 1mm should go from coil 12v pos to cut-off solenoid and then to electric choke. be aware when tuning that the choke is electric so will be slowly opening the whole time the ignition is on. that has got me a few times. have you checked you have voltage at coil pos or use a known 12 volt source or lead from the battery to test while the engine is running. maybe you know someone with a solenoid you could swap-out to test.
if you are new to these carbs or not, Rob and Daves Aircooled VW Pages are a great resource for this and all things technical aircooled.
cheers, Dave

 

[Arni]

Thanks Dave, yes I've checked that I have a positive from the coil and have swapped a cut off valve from another working engine. As to the engine running before the valve wasn't screwed tight and was probably sucking in air, but my god it runs rich!! and it seems never fully came off choke!!
I'm beginning to think the choke could be horrendously set up wrong so will have a look tomorrow .
Thanks for your advice mate it's good to have another brain helping

 

[purpledog07]

Glad to help, take a quick look at the website I mentioned before, has good info on setting choke, well worth a look.