johnson40hp 2 cycle.changed impeller but no water coming out back of outboard still

[phoneman]

I changer the impeller and although the old impeller didn't have a lot of wear, it was stiff.I thought it would fix the fact I was not getting water to exit out the back of the o/b. and the overheating warning light still comes on.I could feel puffs of air coming out but no water,mist at all.I checked the hole for debris or bugs.I shot water through a hose but it just got me wet.its the hole under the 40hp sticker that looks like a bulls nose.Thermostat? clogged hose? any suggestions,bass season is in full stride. Thanks

[boats.net]

Could be bad water pump housing, blown head gasket(check compression), stuck thermostat or water passages blocked.

[phoneman]

removed thermostat and ran without alarm sounding.Heads were warm but not hot.water exiting hose on side and a stream from front of motor but still not a lot from back but there is a small flow now.i am going for a barrel and see what happens.hope she runs good.