If you're presently using track voltage to power your RK switches, that means at any given time each switch is lighting up 2 bulbs (one in the lockon, one (red or green) in the lever controller) with 18V AC. I'm surprised you haven't had bulb burnouts! As I recall, I measured something like 1 Watt per bulb at normal Accessory voltage. It would be more than that if the bulbs are running at 18V AC... at least 1.5 Watts per bulb or 3 Watts per switch. I'm not sure I got the number of switches in your yard right, but if it's say a dozen switches you're burning 30 Watts just to light them bulbs! Yikes!
Obviously, those 30 Watts (or whatever it is) steals power from your engine(s). So a 100W Z-1000 that is dedicating 30 Watts to keep the switch lamps burning only has 70 Watts to power the engines.
In my opinion, you should immediately (that means Do Not Pass Go, Do Not Collect $200) change how you power your switches to Accessory voltage using the 1034 which is presumably set to something closer to 14V. Now you'll have a full 100 Watts from the Z-1000 to drive your engines.
As an experiment, you could also remove all the switch screw-terminal jumpers (which apply track voltage to the switch). In other words this removes the switch lamp power from the Z-1000 in your existing configuration. This is just a test and of course you can manually rotate the lock-on lamp to change switch position if need be for the test. In any case this would allow the Z-1000 to show its gratitude to you for removing the burden of all those lamps...and I'd think the engines might also start behaving better.
