I had a first test drive with my old faithful Johnson fd-18 18 HP 64 model outboard.<br /><br />It has been on storage for 5 years and I changed impeller on water pump, cleaned and tested the thermostat on boiling water. Thermostat seem to open and close on right temperatures. Old impeller wheel was still ok, but changed it anyway.<br /><br />Now to the problem: When I started her, I noticed some white smoke coming from exhaust relief port after while. There was a little water spray from relief port with white steam. Motor was not running hot as I could hold my hand on block and thermostat housing. Only hot place was upper exhaust foot (exhaust part of leg. Then I took thermostat away.......... white smoke disappear and exhaust was nice and warm with nice water flow from exhaust relief. But now engine block was too cold. Sea water temperature was about +4 dec Celsius.<br /><br />It seems that my water circulation system is blocked from somewhere on bypass and water is circulating only trough thermostat. Does anyone know any stuff that I could use to dissolve blockage?<br /><br />Tumpaa
