Over heating?

I have a newly over hauled 1997 Honda Accord 4 cylinder non vtect engine. With new water pump, timing belt, water pump belt, Radiator, piston rings, bearing and all the good stuff.

My problem is the car tends to over boil on the coolaning system. I live on Guam where it’s like 80-90 degree all year long. I took out the thermostat so I know there is no blockage in the cooling system. I jumper the tstat wire so the two fans stays on all the time that the car is running.

When I check the coolant in the morning it seems that is low. I put coolant in the morning and at lunch time I'll check again and it'll be low again. I don't have any coolant leaks from any of the hoses. The only place that I see coolant is around the radiator cap and reservoir. When I take off the radiator cap with the car running there is a good circulation in the cooling system.
I don’t know what else to check. Any ideas?