Hi, I am looking for advice about my Yale GP050 forklift, its a 2001 model with the LPG impco 100 carburator on it.
I have just bought it from a liquidation sale and have got it running on the lpg gas. It takes maybe a minute of cranking first thing in the day but after it has been started and running it starts on the button and actually runs pretty smooth.
When renewing the lpg regulator I have noticed it has a petrol tank with a supply pipe for the petrol going into the carb via an inline filter and what looks like a pump attached onto the cylinder head where I am assuming in is being driven from, then between the pump and the carb there is a brass component which i dont know what function it serves (could it be a non return checkvalve or something??)
Anyway, the petrol tank is empty and I have never put any petrol into the machine.
My question is, should the petrol tank have petrol in it at all times so the engine can run on petrol if no gas is available and possibly for cold starts using petrol then switching over to lpg?
Is this carburator able to run on either petrol or lpg as both of these fuels appear to be plumbed into the carb? does this switchover happen automatically or has it to be done manually?

Many thanks,
William.