Here is the long story...
I bought a used boat last year and have been running it for a few months this year. One day the temperature climbed up rapidly to 210 degrees. I found the raw water pump had failed (the blades had shredded and were nowhere to be seen) so I replaced it with a new one. At the same time I went to check the thermostat only to find that it was missing. I purchased a new thermostat and ran the motor. The temperature started to climb to 200degrees. I tried removing the thermostat and running it as before and everything appeared normal (and yes I did check the stat to see that it was opening at the proper temperature). I took thermal readings on the block and found cooler temperatures at the sensor location but readings as high as 190 at other areas (I tested the sensor as well and it works fine). The lines to the raw water pump are cool so we are getting water, however, the lines from the recirc water pump seem to have very little flow (I can compress the line by simply squeezing it) and no pressure. I did the best I could to check for obstructions even to the point of using a shop vac to draw any water (and bits of blades) out of the block. Everything seemes clear. I had taken apart the recirc water pump as well but everything looks good. No slop in the bearing, no leaks, impeller looks solid as well although I could only see the back side of it without pulling the bearings. Is it possible there could still be a problem with it (I would expect to see more flow)? I would think if I had more flow recirculationg through the block my problems would go away. Any thoughts?
I bought a used boat last year and have been running it for a few months this year. One day the temperature climbed up rapidly to 210 degrees. I found the raw water pump had failed (the blades had shredded and were nowhere to be seen) so I replaced it with a new one. At the same time I went to check the thermostat only to find that it was missing. I purchased a new thermostat and ran the motor. The temperature started to climb to 200degrees. I tried removing the thermostat and running it as before and everything appeared normal (and yes I did check the stat to see that it was opening at the proper temperature). I took thermal readings on the block and found cooler temperatures at the sensor location but readings as high as 190 at other areas (I tested the sensor as well and it works fine). The lines to the raw water pump are cool so we are getting water, however, the lines from the recirc water pump seem to have very little flow (I can compress the line by simply squeezing it) and no pressure. I did the best I could to check for obstructions even to the point of using a shop vac to draw any water (and bits of blades) out of the block. Everything seemes clear. I had taken apart the recirc water pump as well but everything looks good. No slop in the bearing, no leaks, impeller looks solid as well although I could only see the back side of it without pulling the bearings. Is it possible there could still be a problem with it (I would expect to see more flow)? I would think if I had more flow recirculationg through the block my problems would go away. Any thoughts?
