[Ironangel]

A proven home made penetrant is a 50/50 mix of ATF and Acetone. I like to take it a step further and add an equal amount of Marvels Mystery Oil. While your running them valves give them stems a liberal dose of the above mixture. And while your right there with the socket wrench, swing that rocker off the top of the valve stem and hit the top of the valve stem with a hard rubber hammer or the end of the wooden handle of a 4lb hammer. Just a couple of whacks hard enough to open and close the valve a couple times. Do that to each valve paying attention to the sound of each valve. Keep them stems wet with the penetrant while you do this. After you get the valves adjusted and the motor running, pour a little MMO down each throat of the carb. You can follow up with some SeaFoam down the carb to help that MMO get to them valves as well as clean things up a bit. Make sure those push rods are open and the MMO in a squirt bottle will help getting the oil in the ends of the rods and delivered right down to the lifter that may be dry or dirty. Inline fours such as the Z1 are notorious for carbon build up and a squirt through the exhaust ports and in the intake ports gets right on them valves, and the hammer handle trick will usually jar any carbon chunks loose and reseat the valve. Always use an oil with ZDDP in it such as Mag-1 or Valvoline, I'd use a 5w30 with a quart of Rislone or MMO in the crank case...