I check the impeller it's looks good, as I was taking the lower unit off,I notices the largest rubber hose was unhooke behind the out drive. could that's be the problem

There is only 1 hose. plus the drive, exhaust and shift cable bellows. the hose is the cooling. if the hose was off you were running the motor dry. Makesure you didn't melt the plastic water tube from the top of the pump if you got it that hot.