mrmamiller
Petty Officer 2nd Class
- Joined
- Mar 7, 2011
- Messages
- 167
Rather than open an old thread, I thought I'd start over, now that I've had my motor on the water rather than just muffs.
I'm having cooling/heating issues with a 1986 Johnson 110HP motor. I am the original owner and the motor has been used in fresh water only and has seen virtually no sand or dirt.
Currently, I have engine temps which are too low. The motor had major cylinder work at a BRP authorized service marina 1 1/2 years ago, after which I had intermittent overheat alarms. I recently took the motor back to have the intermittent overheat problems diagnosed and repaired. They replace the thermostats/gaskets ONLY, according to their bill. Now, I have temperatures which appear too low. I am monitoring head temps with attached thermocouples with a digital readout as well as with an infrared gun. Temps from the two measurement types agree.
In the water at 600 RPM idle, temps never exceed 112 (port) and 113 (stbd). At 4800 RPM, 39 MPH for 1 minute, temps are 120 (port) and 126 (stbd). Temps drop back down to 110-113 degrees when running at idle speed in gear.
Visible water indications are a pee stream with good force and water spray coming out the holes directly beneath the motor cowling.
When running on muffs for 1 minute, temps around 99 degrees, I noticed that water comes out the holes directly above the anti-cavitation plate. As I recall, water never used to come out these holes until the motor had reached thermostat temperature (140 degrees).
On muffs, I used the IR gun to monitor head/block temps in a variety of locations to see if there were any hot/cold spots and nothing exceptional was found. I was suspecting deflector problems during the motor rebuild.
I am leaving soon for a fishing trip and don't really have much time to effect a repair if it is needed, so I am wondering if I am doing much harm by running low temps. I suspect I only need to worry about excessive carbon build-up at low speed. (The 110HP will mostly be used for high speed operation). After my trip, I expect I will need to get this resolved.
My current thought is that the relief valves are stuck or were left out.
Any thoughts? Thank you.
I'm having cooling/heating issues with a 1986 Johnson 110HP motor. I am the original owner and the motor has been used in fresh water only and has seen virtually no sand or dirt.
Currently, I have engine temps which are too low. The motor had major cylinder work at a BRP authorized service marina 1 1/2 years ago, after which I had intermittent overheat alarms. I recently took the motor back to have the intermittent overheat problems diagnosed and repaired. They replace the thermostats/gaskets ONLY, according to their bill. Now, I have temperatures which appear too low. I am monitoring head temps with attached thermocouples with a digital readout as well as with an infrared gun. Temps from the two measurement types agree.
In the water at 600 RPM idle, temps never exceed 112 (port) and 113 (stbd). At 4800 RPM, 39 MPH for 1 minute, temps are 120 (port) and 126 (stbd). Temps drop back down to 110-113 degrees when running at idle speed in gear.
Visible water indications are a pee stream with good force and water spray coming out the holes directly beneath the motor cowling.
When running on muffs for 1 minute, temps around 99 degrees, I noticed that water comes out the holes directly above the anti-cavitation plate. As I recall, water never used to come out these holes until the motor had reached thermostat temperature (140 degrees).
On muffs, I used the IR gun to monitor head/block temps in a variety of locations to see if there were any hot/cold spots and nothing exceptional was found. I was suspecting deflector problems during the motor rebuild.
I am leaving soon for a fishing trip and don't really have much time to effect a repair if it is needed, so I am wondering if I am doing much harm by running low temps. I suspect I only need to worry about excessive carbon build-up at low speed. (The 110HP will mostly be used for high speed operation). After my trip, I expect I will need to get this resolved.
My current thought is that the relief valves are stuck or were left out.
Any thoughts? Thank you.
