More then likely, since the jet has set for 4 years you have an internal leak in one or more of the cylinders. Either on the doors or the gear. Only way to find it is to pressurize the system and start pinching off lines in to the different areas on the jet then try the gear until you isolate it. You will find which cylinder is leaking when you pinch it off the system will work. The Up valves work great but you can not have any internal cylinder leak by or it plays havoc with them.
Joe Lewis
Kingtech
K-80, K-140, K-180
Owner