We have a Genie S-60 which takes about 3 minutes to completely extend the boom. Same for retracting. I've tried adjusting the potentiometer on the joystick without success. Same symptoms when using the ground controls. Engine RPM has no impact either. Any idea what I could check?
Being an access machine I would expect it to have a positive pressure check valve on the cylinder... I would check there. Is it a recently developed problem? progressively worse? never been fast?
I have owned the machine for 4 years and it has always been slow. The normal full extension is around 60 seconds.
I have an idea it is in the proportional valve coil, but, I have no idea how to test.
http://manuals.gogenielift.com/Parts And Service Manuals/data/Service/Stick Booms/48412.pdf Section 10-1, page 7-38, or in the PDF file page 216, shows the manifold and the Flow regulator valves, #7 (G) is the one for boom extend retract, either it's defective, or the wrong one is installed in that port. The one next to it is for boom up/down, swapping those two will tell you if that's the problem if the extend/retract speeds up but the lift/lower slows down. They may be marked for flow on the end?