Float level Zenith updraught Carburettor

[john williams]

I agree that sounds like the correct level, but to clarify you need to remove the main jet, replace the screw in plug and the fuel should sit 1mm below the top of the tube the main jet fits into. You can of course measure all this with a vernier and make up at measuring tube as Jim describes which is far easier than setting up a remote tank on the bench and viewing the main jet down through the choke tube.

Thank you again Jim, and Ian. I now have the spec's I need to check the level accurately. John