tach not always working

MASTER Brian

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Mar 26, 2006
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The tach on my evinrude XP150 doesn't always give a reading. Something had chewed up some wires in this boat, prior to me purchasing it, and I'd like to try troubleshooting this from the motor, but I don't know where to start. Where on the motor are they pulling the tach reading?<br /><br />Normally, it's low RPM's that don't register, like at idle speeds. Once underway, I normally get what appears to be a good reading. <br /><br />Any ideas??
 

MASTER Brian

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Re: tach not always working

I was told this could be a sign of the stator, I believe, getting ready to go out. Is there a way to test and find out? I currently am tearing the motor apart for a rebuild, so now is the perfect time to replace if need be, but for $200 I don't want to replace just to replace, like I said it may just be a chewed up wire and at this point I can't run a new wire to test that theory.
 

imported_bjs

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Re: tach not always working

my tach was doing the same thing my gauge was bad i think you can take the tach to marine shop they can test the tach shady creek marina sells ranger boats.im not sure about crestview marine give a call.
 

eurolarva

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Re: tach not always working

Most tachs take the signal off the voltage regulator/rectifier. I doubt the stator would have anything to do with this. If your stator were going out you would feel it instead of seeing it being dead on the tach.
 

MASTER Brian

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Re: tach not always working

Originally posted by race fan 8:<br /> my tach was doing the same thing my gauge was bad i think you can take the tach to marine shop they can test the tach shady creek marina sells ranger boats.im not sure about crestview marine give a call.
I'll see if I can get someone to test it. I've been using Wichita Marine for misc parts, because they are an OMC dealer and closer to me.<br /><br />I guess I could also see if I can do an ohm test on the wire to see if it is possibly shorting across.
 

MASTER Brian

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Re: tach not always working

Originally posted by eurolarva:<br /> Most tachs take the signal off the voltage regulator/rectifier. I doubt the stator would have anything to do with this. If your stator were going out you would feel it instead of seeing it being dead on the tach.
Maybe it's the volt reg that he said, I honestly can't remember. I just know the piece was about $200 new. Would the volt reg show on the tach? <br />Thanks!
 

Barnacle_Bill

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Re: tach not always working

Originally posted by eurolarva:<br /> Most tachs take the signal off the voltage regulator/rectifier. I doubt the stator would have anything to do with this. If your stator were going out you would feel it instead of seeing it being dead on the tach.
The actual signal for the tach is an AC pulse from the stator. That same AC pulse also goes to the rectifier for charging voltage. Tachs are normally connected to the rectifier simply because it is a convienant place to make the connection.
 

MASTER Brian

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Re: tach not always working

So would the tach not always working be a sign of something going out or just a bad tack? It seems to workfine at higher RPM'S.
 

Barnacle_Bill

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Re: tach not always working

Since you said you had some chewed up wires, I would explore that first.
 

MASTER Brian

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Re: tach not always working

Originally posted by IBNFSHN:<br /> Since you said you had some chewed up wires, I would explore that first.
That's what I'd like to do, problem is motor is torn down to replace the P.H., so I can't easily run a new wire and test to explore that route. <br /><br />I think I'll pull the tach and see if the boat shop can test it. If it's ok, I'll run the new wire. If anyone knows how to test the electrical system, I'd like to see if I can test that as well. Right now is the time to replace anything that needs replacing, so I'm not down any longer than need be.
 

eurolarva

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Re: tach not always working

If motor runs fine the stator is not your problem. If the AC signal is not generated from the stator the motor will not run or run like crap. With the motor running put a DVM set to DC volts and see if it is charging the battery. If voltage does not go above 13 volts your regulator/rectifier is shot and your tach will not work.
 

MASTER Brian

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Re: tach not always working

Originally posted by eurolarva:<br /> If motor runs fine the stator is not your problem. If the AC signal is not generated from the stator the motor will not run or run like crap. With the motor running put a DVM set to DC volts and see if it is charging the battery. If voltage does not go above 13 volts your regulator/rectifier is shot and your tach will not work.
Will check that out, thanks!! It may be a few weeks until the motor is back together, but I'll post a reply!
 
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