Sorry,
I have a non-compete agreement with Watcon, and can no longer offer tech support.
John and I talk every day, and we discuss all matters.
I can tell you that most of you guys are having pop-off problems.. You need to purchase the correct srings from John, and follow his jetting reccommendations exactly!
Once you have the carbs at his specs, you will have the best luck removing the fuel tank check valve. Your fuel requirements can vary, depending upon the type of fuel you use, and your ambient temperature, location, etc but the Watcon kit (complete kit) works well in most areas.
Best regards,
Randy