1980 Mercury 110 9.8HP bogs out at WOT after 15 mins running

[northcountryman]

I have a 1980 Mercury 110, 9.8 HP. It bogs out at WOT after running for 15-20 mins. Pulling out the choke when it is bogging doesn't help. If you let it sit for a few mins (5-10) it will restart and run OK again for another 15-20 mins. Any help would be appreciated

 

[northcountryman]

Did compression test. 90 PSI each cylinder. New plugs, thermostat. Cleaned carb and installed new kit. Engine running at 145 degrees with laser thermometer at cylinder wall. Baffled because it runs so well until it bogs out. I neglected to state that it will also stall after trolling at low speeds. Have to let it sit for 5-10 mins and it will restart.

 

[MH Hawker]

When it bogs try pumping the ball it sort of sounds like the fuel pump

 

[northcountryman]

I tried pumping the ball and choking it when it starts to bog down. Still bogs down and quits.