Yous guyz really oughtta try the Marvel Mystery Oil soak! When your VX has some down-time, (couple-o-days) remove the spark plugs and pour a couple of ounces of MMO down each cylinder and rotate the crank a few times and then let it soak for a few days. Replace your plugs and fire it up and let 'er smoke! Replace your plugs with a fresh set and see if that clears your plugged oil return holes. It absolutely frees sticky rings so I can't see how it wouldn't help unplug those pesky oil return holes...