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Old 05-17-2018, 12:22 AM
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tkwalker tkwalker is offline
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Join Date: Apr 2005
Location: Lebanon, Tennessee
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Smile A little more info .. <'TK><

Originally Posted by Texas_Rig View Post
This is an update on my motor. I have a Mercury 175 EFI. These motors will not pee very well until the thermostats open. I noticed on Saturday that my motor was not peeing as well as it should. I brushed it off as my motor wasn't warm. It would pee ok at 5000 rpms. But I did check the hose for blockage that day and it was clear. Yesterday I checked it again and it was clear. My tube connects tge motor to a plastic piece on the calling(spelling?). I took the plastic piece off and it was 90% clogged with what appeared to be moss. I cleaned it out and the poppit valve. I took the boat to the lake today and ran it for 20 minutes and it ran great and peed great. It also had a little more water pressure.

Here's what my non mechanical mind thinks happened. I think the hot water was building up in the motor because it couldn't escape and I was getting a temperature warning with the beeps. Does this make sense to any of you guys that have any understanding about boat motors? The boat appears to be fine now.
First off in my experience, BUC is right, I have found Merc's draw Dirt Dobbers like Magnets.. 10 to 1 over other brands and I don't know why!! ... The pee tube is called the "tail tell" ... and really it's primary purpose is to indicate that you do have water flow through the motor that can be physically seen with the EYE, It is a parallel water flow ckt from the main cooling flow. The thermostat does not enter the picture when it comes to Tail Tell Flow.. If you notice, even before the motor hits and starts with just the Electric starter motor you have Tail Tell flow, and immediately after it starts and it is dead cold... Note: Outboard Thermostats don't control water flow like automotive thermostats do.

But with that said ... It could be totally stopped up and you could still have sufficient water flow through the engine and the primary discharge of the water is either through the prop or exhaust housing port depending on Brand, model and year. Now if the Tail Tell was stopped up your water pressure would increase not decrease. Example. Like putting your thumb over the end of a Garden Hose, restricted water flow but increased pressure... As far as the temp sensors, The are usually located near the cylinders and Heads which get the hottest. I am always suspect of Water pump impellers when it comes to over temp and flow indications.

TR didn't you just have your lower unit rebuilt again .. I am sure your mechanic installed a new Water Imp. It's right there on top when he dropped the unit... <'TK><
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