I searched and could not find an answer here - so i'll throw this to the experts.
Boat is run in salt water only.........impeller is less than year old.
two days ago, i lowered boat into the water and started the boat. While it was idling, i ran into the house to get something - i heard the overheat alarm go off. It has never done that before. It's got 160 hours on it 2011 model year.
I went out to the boat and the motor had shut off. I restarted the boat, no issues, and idled in the no-wake sone for about .2 of an hour. I have a NMEA2000 set up on my Garmin 441S and looked at the engine gauges. I noticed the the temp gauge creeping up... I watched the gauge get to about 180 and the alarm kicked in - so i shut the boat down.
I then watched the gauge and it went down fairly quickly - so i started the motor back up - i made it out to the deep water and went up to 5000 rpm. The alarm went off after a few minutes and the gauge said 180 degrees. I went down to idle, the alarm shut off and the gauge remained right around 175-180 - no alarm.
While idling - i went a felt the water coming out the pee-hole - good strong stream, not hot, but not cold either.
I idled about 10 minutes and got boat home, no issues.
I went to the local honda shop and spoke with the guy at the parts counter, i couldnt talk to a mechanic. The parts person was briefed on what occurred and impeller age. He thought could be the thermostats. I bought two new ones, and gasket.
Yesterday, started boat up - no issues - after .5 hours, of high rpm 5000, i watched the gauge finally get up to 180'ish and the overheat alarm activated. I reduced to idle and went home to put in the new thermostats. I confirmed the over heat alarm and looked at the warning light, the green oil pressure light was glowing green - and the red temp light was on - also, the GPS NMEA said OVERHEAT WARNING #1 (only have 1 engine)
I removed the thermostat cover, there was some corrosion on the old thermostats, and little in the housing. I cleaned up the housing - and installed new ones and replaced the cover. Checked for leaks, all was good.
Took boat out - and watched the gauges - i saw the temp gauge on the GPS come up to 150 - then creeping up a little more, then it stayed at 175 for a long while - i started to do 5000 rpm's to see what was going to happen - the peehole was streaming good, temp of water coming from peehole was same as before - not hot - but not cold.
I kept doing the 5000 rpms for about 30 minutes and i watched the temp gauge creep up to over 200 - no alarms, no red lights no warnings -
I slowed to idle - and the temp went down between 175 and 200 and i idled home - not knowing what the heck was going on. I shut down the motor, turn the key to on position and got the normal two beeps -so the alarm horn works
I dont know what temp the boat should run at - but i dont think it should be running at 200 degrees - i've heard you can cook a motor that hot.
I have not dropped the lower unit to check the impeller - it seems fine based on the peehole stream being fairly strong at idle and at higher rpms.
Any suggestions on what it could be or what i should look for??
Thanks in advance for your assistance
jeff
Boat is run in salt water only.........impeller is less than year old.
two days ago, i lowered boat into the water and started the boat. While it was idling, i ran into the house to get something - i heard the overheat alarm go off. It has never done that before. It's got 160 hours on it 2011 model year.
I went out to the boat and the motor had shut off. I restarted the boat, no issues, and idled in the no-wake sone for about .2 of an hour. I have a NMEA2000 set up on my Garmin 441S and looked at the engine gauges. I noticed the the temp gauge creeping up... I watched the gauge get to about 180 and the alarm kicked in - so i shut the boat down.
I then watched the gauge and it went down fairly quickly - so i started the motor back up - i made it out to the deep water and went up to 5000 rpm. The alarm went off after a few minutes and the gauge said 180 degrees. I went down to idle, the alarm shut off and the gauge remained right around 175-180 - no alarm.
While idling - i went a felt the water coming out the pee-hole - good strong stream, not hot, but not cold either.
I idled about 10 minutes and got boat home, no issues.
I went to the local honda shop and spoke with the guy at the parts counter, i couldnt talk to a mechanic. The parts person was briefed on what occurred and impeller age. He thought could be the thermostats. I bought two new ones, and gasket.
Yesterday, started boat up - no issues - after .5 hours, of high rpm 5000, i watched the gauge finally get up to 180'ish and the overheat alarm activated. I reduced to idle and went home to put in the new thermostats. I confirmed the over heat alarm and looked at the warning light, the green oil pressure light was glowing green - and the red temp light was on - also, the GPS NMEA said OVERHEAT WARNING #1 (only have 1 engine)
I removed the thermostat cover, there was some corrosion on the old thermostats, and little in the housing. I cleaned up the housing - and installed new ones and replaced the cover. Checked for leaks, all was good.
Took boat out - and watched the gauges - i saw the temp gauge on the GPS come up to 150 - then creeping up a little more, then it stayed at 175 for a long while - i started to do 5000 rpm's to see what was going to happen - the peehole was streaming good, temp of water coming from peehole was same as before - not hot - but not cold.
I kept doing the 5000 rpms for about 30 minutes and i watched the temp gauge creep up to over 200 - no alarms, no red lights no warnings -
I slowed to idle - and the temp went down between 175 and 200 and i idled home - not knowing what the heck was going on. I shut down the motor, turn the key to on position and got the normal two beeps -so the alarm horn works
I dont know what temp the boat should run at - but i dont think it should be running at 200 degrees - i've heard you can cook a motor that hot.
I have not dropped the lower unit to check the impeller - it seems fine based on the peehole stream being fairly strong at idle and at higher rpms.
Any suggestions on what it could be or what i should look for??
Thanks in advance for your assistance
jeff