We've got the mid-winter blues up north - most of our lakes now contain 'hard water'. 
So, I'm looking over a buddy's 1982 DT25. It was factory designed with no tell-tale, so I'm wondering about the cooling water.
He's freshly installed a new water pump impeller, but when we run it on muffs we don't get any water coming out the
prop hub assuming that's where it should show up at.
- Is it OK to run this motor on muffs, or must it be submerged? Remember the hard water issue.
- Shouldn't we see water coming out at the hub, and maybe more water when the thermostat opens up?
- What temperature should the thermostat open at? We've used an infra-red thermometer, but shut down the motor
when the head temperature reached 200 degrees.
- Does anyone have a water flow diagram for these old motors?
- Not having a tell-tale water stream is uncomfortable for me. I'd like to confirm there's sufficient cooling water every
time the motor is started.
- Has anyone added a small hose fitting to the exhaust cover with a small hose coming out of the housing?
I'd sure like to add a tell-tale to this motor.
TIA - sorry for all the questions!
So, I'm looking over a buddy's 1982 DT25. It was factory designed with no tell-tale, so I'm wondering about the cooling water.
He's freshly installed a new water pump impeller, but when we run it on muffs we don't get any water coming out the
prop hub assuming that's where it should show up at.
- Is it OK to run this motor on muffs, or must it be submerged? Remember the hard water issue.
- Shouldn't we see water coming out at the hub, and maybe more water when the thermostat opens up?
- What temperature should the thermostat open at? We've used an infra-red thermometer, but shut down the motor
when the head temperature reached 200 degrees.
- Does anyone have a water flow diagram for these old motors?
- Not having a tell-tale water stream is uncomfortable for me. I'd like to confirm there's sufficient cooling water every
time the motor is started.
- Has anyone added a small hose fitting to the exhaust cover with a small hose coming out of the housing?
I'd sure like to add a tell-tale to this motor.
TIA - sorry for all the questions!
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