Hi the valves are hard to get right the lift and seal (I know I have been trying to build a few) even on my Cheddar pump it stoped working because I used some water that was just filterd, it cloged the valve up in two fills, I was at Cheddar and someone showed me thefine particals that where holding the valve open, taught me a lesson so it is proberley just a valve not sealing, i am trying nitride balls now (Ihope it's spelt rite) when I start work on it again. by the way your engine is very nice and great to watch.
Peter
