1979 85 hp evinrude

[bishopcherrycoke]

Hello again. I have a 2 part question. 1st, I bought a tach for the old evinrude and hooked up power, ground and the grey wire for signal and it doesn't work. Looks pretty but stays at 0. It jumps slightly when the ignition is keyed but that's it. My second question is does anybody have experience with props on a 16 foot small glass boat? Its a 1975 checkmate mx-16. I have a 14" 17P alum prop now and I get to 39mph (gps) in a hurry with 15 gallons of gas and 2 adults. Hoping to get a little more top end without hurting the motor. Any help is really appreciated.

 

[boobie]

Re: 1979 85 hp evinrude

The charging system on the mtr may not be working which would cause the tach not to work. Get the tach to work and then prop it out to the wot mtr specs.

 

[bishopcherrycoke]

Re: 1979 85 hp evinrude

I'm pretty sure the charging system is ok. I have 2 battery's and the lights and radio are almost always on and the battery's never go dead.

 

[emdsapmgr]

Re: 1979 85 hp evinrude

You need to confirm the voltage in your system. Once the engine is started, it does not use the battery, except for the power trim. Running it with no charging system may take it a long time to drain the battery. That engine has an (unregulated) rectifier- only. After running the engine for 20 minutes the charge on the battery should increase to 16+ volts.