Trim gauge

Jeffafa

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Jul 10, 2021
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1984 Mercedes (freedom marine) mercruiser 3.0 120hp Question: I have a trim sensor and limiter but no gauge .. I don't even know if my boat came with a gauge..could someone have removed it and installed an engine hours gauge which does not look original? Would the sensor and limiter serve another purpose? Not sure if I should buy a gauge and wire it in or just go without.. any thoughts are appreciated!!
 

Scott06

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1984 Mercedes (freedom marine) mercruiser 3.0 120hp Question: I have a trim sensor and limiter but no gauge .. I don't even know if my boat came with a gauge..could someone have removed it and installed an engine hours gauge which does not look original? Would the sensor and limiter serve another purpose? Not sure if I should buy a gauge and wire it in or just go without.. any thoughts are appreciated!!
having had boats with out gauges or non functional gauges I would not bother. The limit switch is to make sure you do not over trim at speed and is somewhat needed
 

Chris1956

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Mar 25, 2004
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What Scott means is that the trim gauge moves too slow to be effective, and can only give approximate positions of the drive, say full down and full up.

Of course, you can hear full down and full up, by the sound of the PTT motor.
Also, you want to trim the boat by feel. When she handles lightly, she is near or at optimum trim. If she porpoises, she is over trimmed.

The trim sensor on the Alpha drives (not sure about your's), was on the opposite tilt pivot point of the outdrive. It was a copper pointer riding on a variable rheostat coil of wire. They rotted out all the time as they were exposed to water.
 

Scott06

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What Scott means is that the trim gauge moves too slow to be effective, and can only give approximate positions of the drive, say full down and full up.

Of course, you can hear full down and full up, by the sound of the PTT motor.
Also, you want to trim the boat by feel. When she handles lightly, she is near or at optimum trim. If she porpoises, she is over trimmed.

The trim sensor on the Alpha drives (not sure about your's), was on the opposite tilt pivot point of the outdrive. It was a copper pointer riding on a variable rheostat coil of wire. They rotted out all the time as they were exposed to water.
That's not what I meant... meant that you dont need a trim gauge , nice to have yes but certainly would spend time and money to put one in or replace the sender unless I was doing bellows anyways.
 

Chris1956

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Sorry to put words in your mouth Scott. I thought you were going in a different direction.

I have had a trim gauge on a MerCruiser and on a Johnnyrude. Neither were worth a darn, for the reasons I stated.
 

Scott06

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Sorry to put words in your mouth Scott. I thought you were going in a different direction.

I have had a trim gauge on a MerCruiser and on a Johnnyrude. Neither were worth a darn, for the reasons I stated.
Wasn't disagreeing its only nice to know full up and full down rest of time trimming by feel
 

Chris1956

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I could always hear when the motor was full up or full down. The PTT motor changes tone.
 

Jeffafa

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Jul 10, 2021
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12
Good to know guys, thanks for the input. Yea I've just gone by feel and sound with this one, and this is my first boat so I wasn't sure if it was nice to have but sounds like I'll just go without the gauge. Thanks!
 

nola mike

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Apr 22, 2009
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I never even reconnected the wires when I replaced my engine 4 years ago. Last year i replaced the gauge with a much more useful a/f gauge (O2 sensor still working Scott, I'm going to keep it in till it fails). My boat will porpoise waaayy before I'm anywhere near the trim limit
 
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