Tachometer Troubleshooting

fixmyevinrude

Petty Officer 1st Class
Joined
Sep 18, 2008
Messages
205
1988 Evinrude 150 XP
1988 Basscat Pantera 2


Had boat out for first time yesteday since recent purchase. Tacohmeter was reading very erraticly. Half throttle reading was sometimes 6000 RPMs. I feel certain the tach is reading incorrectly. I would appreciate any help in troubleshooting. Any troubleshooting sequence would be helpful.
 

gm280

Supreme Mariner
Joined
Jun 26, 2011
Messages
14,585
Does you tach have a selector type switch on the back of it to select for different engines? If so, turn the selector switch between the different selections a few times and then set it back at the original setting. Some times the contacts on those selection switches get some dirt on them and makes then erratic... Other then that, make sure all the wires are tight both on the tech and from the engine... JMHO!
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
gm280 has a good comment. If that does not help, you may have a bad rectifier/regulator. That device recharges the battery and also sends a signal to the tach. If the tach is working, but acting up-it's possible that the device is bad. That likely means the battery is not being recharged.
 

V153

Lieutenant Commander
Joined
Apr 16, 2011
Messages
1,764
Check rectifier/voltage regulator. Check connections first of course.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Check that all your battery cable connections are good, clean and tight.
 

fixmyevinrude

Petty Officer 1st Class
Joined
Sep 18, 2008
Messages
205
gm280 Yes the tach does have selector switches on the back,.sounds like a great idea. Thank You
emdsapmgr Is there any test I can do to check the rectifier/regulator?
V153 & boobie Connections are all clean and tight and a new battery was installed this spring

Boat has sat for about 3 years since last being used by previous owner so I dont have a lot of history on it.
 
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