2001 san boat temperatue

01 super air with about 500 hours.

boat has been out five times this season. The second time it seemed to run hotter than normal. Gauge usually parked at 160 and never moves. This time it was creeping more toward 180, but it didn't do it right away, The temp increased the longer we were out. Got back in and changed the impeller (was in one piece with all fins). checked water pick up and didn't see any blockage, blew into strainer inlet hose to water pickup (backwards) and felt no blockage

third time no difference. impeller change had no affect. Boat started out fine and slowly heated up the more we drove it. this time was close to 200 or 205, so ended up idling home.

came back and changed t-stat and made sure strainer was tightened. Old t-stat opened right at 160 in hot water (stove). Went out the fourth time just to test and couldn't get it to go above 170 or so but didn't drive it that long.

fifth time- . seemed fine and then started heating up. climbed up to 200 but at idle goes back down to 160. Put new gasket in strainer at lake and then drove it around. at about 34mph for 15 min it was stuck at 190. went to idle and went to 160. went 25mph for 10 min and went to 185-190. could not get it to go back up to 200 after new strainer o-ring, back to idle and goes to 160.

it seems like it is doing the opposite of "bad impeller" symptons.

any ideas??

glad you got it figured out. I have '99 super air and it runs right at 160.