tach problem

[gbrummund]

89 Evinrude GT 100<br /><br />Tach use to be intermitent, now does not work. It zero's out when key is on, it sees 12 + volts at tach, it shows the rpm's when the motor is spinning via the starter but when the engine fires up it drops back to zero and does nothing.<br /><br /><br />Any ideas?<br />Thanks

 

[rickdb1boat]

Re: tach problem

Is the engine charging properly? Got a voltmeter gauge or just a voltmeter to check it out? You should read somewhere around 13.5 volts when running. That's a steady 13.5 volts, not jumping around. I would also be suspect of the gauge itself. You might see if you can borrow a test tach from you local dealer for a small fee and verify yours is good. Also, make sure all the connections to and at the tach are good and tight and not corroded.

 

[gbrummund]

Re: tach problem

Rick , thanks for the reply, work has been so busy that i have not had a chance to check out the voltage untill now. The voltage started at 12.5 and slowly worked up to 13.68 to 13.70 and stayed there. Whats odd is that while the engine is cranking, the tach reads the rpm untill it starts and then it drops to 0. If i pull out the overboard switch so the engine will not start while i crank it over, the tach shows the corresponding rpm? For some reason when the engine fires up the signal to the tach is lost. I'm going to trace the signal wire at the tach down the line to see if i can find a loose connection. <br /><br />thanks

 

[M Kanak]

Re: tach problem

I once had a Z28 that mirrored your tach problem exactly. It would zero out, show cranking rpm and very occasionally would flicker like it wanted to work. The problem was that the wire was shorted to the body and would work until the demands were higher. Check your connections and trace the wire itself back and I'm sure you will find your problem. A tachs a tach. Good luck.

 

[gbrummund]

Re: tach problem

ok, fixed. I traced the signal wire down the line with my ohmmeter and found a failed pin connector. Never really thought about how these worked untill now, good learning experience. Could not have done it with out this great forum. <br /><br />Thanks guys

 

[rickdb1boat]

Re: tach problem

Good Job troubleshooting!!!!