Suzuki motor doesnt seem to pump water in during cool water temps.

[Midcoast]

I have a 1997 Suzuki 2 stroke 40 hp motor. During early spring ( April), the water temp. in MN is colder. At first start it would take my motor a good 3 to 5 minutes before the cooling water pumped in comes out of the motor. Often times, I would see smoke coming out of my engine head. The only way the water will come out is if I put my motor on forward, and once the boat starts moving the cooling water will then come out of my motor. This only happens in really cold water temps like during April and only on the first start of the day. Throughout the day when I start my motor, water will come out within 5 to 10 seconds, and also later on in the season at first start water comes out of my motor right away within 5 seconds or so.

Any ideas? Does it just need a new water pump or is this normal since it is cold?? Could it be the thermostat? I heard thermostat is expensive.

[boats.net]

I recommend changing the water pump. The impeller maybe too hard for the cold weather.