115 hp Honda low compression and overheats

We have a 115 Honda that shuts down as an overheat condition after 1 minute of WOT after idling for a minute or two the fault goes away. Motor has a new water pump and thermostat. We have run a compression test and the top cylinder is at 150 psi going down to 80 psi for the bottom cylinder. A cylinder leak test shows exhaust valves are leaking on 3 cylinders. The motor has good power and idles well. What could cause the original overheating and cause the valves to leak We have the temp sender out but do not know what Ohm readings be at different temps. All help is appreciated