Curtis Macdonald
New Member
- May 24, 2018
- 25
- Boat Info
- 1990 Sea Ray Sundancer 250DA
- Engines
- 5.7 SE106 stern drive
Hey folks, brand new here and I have a question. I recently bought a 1990 Sea Ray 250DA with the 5.7 single motor/outdrive combination. When I picked up the boat from the marina and loaded it on my trailer, the "over temp" alarm began to sound off while idling to the ramp nearby. The previous owner had stated that he had seen the same issue at full throttle, but if he backed it off a little, the alarm went quiet. Well, it was sounding off for me at idle.
So, I decided to replace the impeller and housing in the SE106 outdrive. I did and found that it really wasn't in bad condition and still had some good flexibility, but I replaced it anyway. I serviced the lower unit with new grease as well, it needed it.
Then I decided to go ahead and replace the thermostat, because that's what he suspected was the issue. So I removed the hoses, then pulled the housing and to my surprise, there was no thermostat present. I also found that the alarm switch, not the temp switch, was damaged. The plastic shroud was missing from the switch but the wire was still attached. So, I'm replacing the gaskets and installing a new 140 degree thermostat this weekend. After examining the way the system operates, is it possible that the absence of the thermostat could make it run hot? Curious if the spring loaded balls going to the exhaust coolant lines weren't sealing well enough, if the exhaust was helping heat up the water and switch on a back feed? I know, goofy question, but I'm looking to solve the overheat alarm or possible actual overheating issue, before I put it back in the water. What else should I check as far as blockage? The belt is tight and the pump looks good externally and this boat has always been in fresh water. Is it wise to go ahead and replace the engine water pump? The boat is showing 767 hours on the meter. Thanks in advance!
So, I decided to replace the impeller and housing in the SE106 outdrive. I did and found that it really wasn't in bad condition and still had some good flexibility, but I replaced it anyway. I serviced the lower unit with new grease as well, it needed it.
Then I decided to go ahead and replace the thermostat, because that's what he suspected was the issue. So I removed the hoses, then pulled the housing and to my surprise, there was no thermostat present. I also found that the alarm switch, not the temp switch, was damaged. The plastic shroud was missing from the switch but the wire was still attached. So, I'm replacing the gaskets and installing a new 140 degree thermostat this weekend. After examining the way the system operates, is it possible that the absence of the thermostat could make it run hot? Curious if the spring loaded balls going to the exhaust coolant lines weren't sealing well enough, if the exhaust was helping heat up the water and switch on a back feed? I know, goofy question, but I'm looking to solve the overheat alarm or possible actual overheating issue, before I put it back in the water. What else should I check as far as blockage? The belt is tight and the pump looks good externally and this boat has always been in fresh water. Is it wise to go ahead and replace the engine water pump? The boat is showing 767 hours on the meter. Thanks in advance!