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  • #16
    Pulled the pressure relief valve , very clean , water jacket very clean as well , no corrosion

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    • #17
      You can also check the exhaust guide plate which connect's the powerhead to the lower unit. If you lift up the pigtail that is tucked away at the back of the motor on the bottom you can check for corrosion or blowthru. Mine was shot, so I had it replaced. Also i had corrosion and blowthru on my block where the head gasket connects to block at the bottom port of my thermostat. You have to pull the heads to check this. I fixed mine with marinetex.

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      • #18
        plate was fine , I completely disassembled and replaced exhaust manifold , oil pan ,. oil pump , pickup ,after my balancer failed. there was no overheating issue at that point .

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        • #19
          Have you checked the cowling for air flow ? I had a wasp nest in mine.

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          • #20
            gsdanno1,

            These motors are unbelievably tough. I believe they can run with a scored piston for quite some time before blowing like my 2005 150 VMAX 2 stroke did.
            I would shoot the cylinder walls with infrared temp gun at WOT and see if any cylinders are above 200 degrees. My cylinder walls were between 125 and 155 degrees at 3800 RPM's. But first I would do a compression test , just for piece of mind. Have you looked at your plugs and what did they tell you ? Job one is to keep that motor from blowing. Job 2 is to fix the alarm.

            JC

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            • #21
              Just to be clear , the test with the YDS was done with the cowling off . As I understand it , the YDS reads data from the ecm , therefore it's getting data that is reported back from various switches and sensors , so seeing how I've verified all the temp sensors ,and thermostat are working correctly, there is a very good water stream coming from the motor and from what I can see there is no corrosion in the water jackets and I replaced anything with even a slight bit of corrosion , I'm almost wondering if it may be fuel related , like maybe a lean condition. Timing is also spot on according to the YDS

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              • #22
                Just pulled the plugs , they look like plugs with 12 hours should look like . Number 2 seemed loose , but no evidence of soot around the base of the threads

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                • #23
                  The sensors can only read the temp where they are located. The cylinder heads and covers have flow grooves in them and are quite small. The 20 psi only reads at the top of the head. The tell tale only tells you that the pump is working fine. I sent you a private message.

                  Joe

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                  • #24
                    What I'm trying to say is that It might be possible that when you did all the work that some debris, piece of gasket or broken off crust got into the passages in the heads restricting water flow.

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                    • #25
                      Ran the motor at 4400 this morning in neutral for about 15 minutes . Temp on the YDS got to 195. With a heat gun , temp at thermoswitch high as 240 , temp at engine temp sensor high as 195 . Oil filter 174. I'm going to take it out this afternoon, but I'm hesitant to have my buddy holding the heat gun at 40 mph with the cowling and the flywheel cover off , especially when trying to check the area where the engine temp switch is as its so close to the flywheel

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                      • #26
                        Originally posted by gsdanno1 View Post
                        Ran the motor at 4400 this morning in neutral for about 15 minutes . Temp on the YDS got to 195. With a heat gun , temp at thermoswitch high as 240 , temp at engine temp sensor high as 195 . Oil filter 174. I'm going to take it out this afternoon, but I'm hesitant to have my buddy holding the heat gun at 40 mph with the cowling and the flywheel cover off , especially when trying to check the area where the engine temp switch is as its so close to the flywheel
                        I am planning to run mine tomorrow and check via the YDS. I don't have a gun so I can't check head temps. Provided I can get my ancient version loaded/working on my new laptop.

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                        • #27
                          ran down the river today , battery in computer died , here are the temps I recorded on the gun. Thermoswitch -180 , top of motor after thermostat-178 , oil filter -180 , engine temp switch - 213 . Going to make another run tomorrow afternoon , and will check head at spark plugs as well as all above

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                          • #28
                            post with temp that read 240 , should have said 140

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                            • #29
                              Es ? If that's the exhaust manifold that runs through the oil pan , i already replaced it

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                              • #30
                                that's what I replaced , mine had a 3" hole in the center

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