crabby_bob
Seaman
- Joined
- Mar 22, 2007
- Messages
- 58
Thanks to everyone who offered advice in my previous thread ( http://forums.iboats.com/showthread.php?t=352317 ) regarding a problem I'm having with my 1988 Johnson 120HP motor.
Based on the information we got my brother and I decided to concentrate on testing the over temp circuitry that feeds into the power pack. The first thing we tested was the new horn. We disconnected the starboard side heat sensor and touched the tan wire to ground. The alarm sounded so that appears to be OK.
We then removed both the port and starboard heat sensors and put them in oil heated to about 203 degrees. We used an ohmeter to verify that the switch would close and found that the starboard side worked but the port side didn't. So we feel the sensor is bad but not bad in a way that would trigger SLOW mode.
The port side sensor has two wires. I believe the tan wire is the over heat sensor but don't know what the black and white wire is for. The temperature range is lower, about 96 degrees F to close and 36 degrees to open. The switch appears to work OK but does anyone know what it's for? It goes into the power pack and my guess is that it's used as an indication to the controller that the engine has reached operating temperature.
We're in the process of replacing the water pump. Removing the gear box was difficult because of the location of the screw that connects the gear shift rod to the head. We were able to get it out and with some wiggling were able to drop the gearbox.
The new pump is in and we've got new gaskets for what appears to be an exhaust port between the gear box and the midsection. The manual calls for the application of some sort of sealant around the rubber seals. Is there something specific we should use. I left the instructions on the Cape so I can't quote the exact words but it called for some sort of rubber sealant.
It looks like reconnecting the shift linkage is going to be a real PITA. We've been careful not to move it and found a section in the manual describing how to adjust it for height. Are there any tricks to getting it up the midsection and reconnecting it to the head?
Thanks,
bob and Ray
Based on the information we got my brother and I decided to concentrate on testing the over temp circuitry that feeds into the power pack. The first thing we tested was the new horn. We disconnected the starboard side heat sensor and touched the tan wire to ground. The alarm sounded so that appears to be OK.
We then removed both the port and starboard heat sensors and put them in oil heated to about 203 degrees. We used an ohmeter to verify that the switch would close and found that the starboard side worked but the port side didn't. So we feel the sensor is bad but not bad in a way that would trigger SLOW mode.
The port side sensor has two wires. I believe the tan wire is the over heat sensor but don't know what the black and white wire is for. The temperature range is lower, about 96 degrees F to close and 36 degrees to open. The switch appears to work OK but does anyone know what it's for? It goes into the power pack and my guess is that it's used as an indication to the controller that the engine has reached operating temperature.
We're in the process of replacing the water pump. Removing the gear box was difficult because of the location of the screw that connects the gear shift rod to the head. We were able to get it out and with some wiggling were able to drop the gearbox.
The new pump is in and we've got new gaskets for what appears to be an exhaust port between the gear box and the midsection. The manual calls for the application of some sort of sealant around the rubber seals. Is there something specific we should use. I left the instructions on the Cape so I can't quote the exact words but it called for some sort of rubber sealant.
It looks like reconnecting the shift linkage is going to be a real PITA. We've been careful not to move it and found a section in the manual describing how to adjust it for height. Are there any tricks to getting it up the midsection and reconnecting it to the head?
Thanks,
bob and Ray
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