Tach question

[Eric H]

I recently installed a 84 140 Evinrude on my boat. With it I installed a brand new teleflex tach and OMC tach harness. When I set the tach to 6p, as per teleflex instructions, it reads way to high. When I set it to 12P it reads close but still sounds a bit high. It will read 7000 at WOT but I know from other v4's I've had it sounds more like 5000. I read on the teleflex site about some other Evinrude models requiring a 4K resistor but it didn't mention the 140. Any suggestions? BTW, I just started browsing this site and I like what I see so far!!

 

[Eric H]

Re: Tach question

I hate to be the first to respond to my own post but after a little research on this site I may have found my answer. I found out a couple of days ago my motor is not charging as the battery barely had enough juice left to get the thing started. Seems that other posts point to the rectifier causing tach/charge probs so I'll do some checking. <br /><br />This also brings up another question. When I installed the motor I found a large 10 ft 10ga wire connected to a terminal block on the right side of the motor. I could not identify this wire via the manuals and all the other wiring seemed correct. There is a smaller red wire going to the battery side of the starter solenoid which I believe is the rectifier output. (not 100% sure though) I called an OMC dealer and he advised the 10ga wire was a switched hot for accessories and it wasn't needed. Being the skeptic, I did run the wire with the main harness but did not hook it up nor have I checked it for voltage. My old 85hp had no such wire and I suspected it wasn't needed. Can anyone clarify this for me? Have I confused you all enough?

 

[OBJ]

Re: Tach question

Hi Eric...<br /><br />If the 10ga. wire looks like an add on, ie, not in the wire harness, then it's probably not needed. The red wire running over to the starter solenoid is the charge wire from the rectifier.<br /><br />If you are experiencing a dieing battery, look for a voltage drain first before replacing the reg/rectifier although the erratic tach would point to the charging system as being faulty.

 

[Eric H]

Re: Tach question

I have fixed the charging problem but the tach still reads high.<br /><br />I found the factory wire from the rectifier to the starter disconnected at the rectifier. The questionable 10 ga wire was connected to the rectifier and I suspect someone had an ammeter connected at some point.