OMC Tachometer and Evinrude 40hp.

My engine is a Evinrude BE40ELCR 1984, I have an OMC Tachometer details are,Aqua meter inst.corp. Roseland N.J. U.S.A. 07068 on back is pulse switch,(pulses per rev) reads from 1 to 6, with details, Set Pulse Switch as Engine Requires. Grey Wire To Pulse Source. Black Wire To Ground. Has wiring with plug attached to go into my OMC control box. Two questions please, Will it work (providing all is well with my engine charging circuit) and what should it be set at on Pulse Switch for this engine? Thank you Lurcher.

Re: OMC Tachometer and Evinrude 40hp.

Yes - the pulse line is fed from the charging circuit and can be connected to the connector on the control box if one is present and that corresponding connection has been made at the engine. The selector on the tach is set to 6P.

Re: OMC Tachometer and Evinrude 40hp.

Many thanks Silvertip, How can I establish if connection is made at motor? and is there any way of checking system with analogue multimeter at the plug in on OMC control box? Great help Lurcher

Re: OMC Tachometer and Evinrude 40hp.

The engine is already wired to the control box, from the engine. That is standard.

Re: OMC Tachometer and Evinrude 40hp.

Thanks DJ, is there anything to be gained from putting meter into control box connection to see if there are any pulses, (engine running of course) before plugging in Tacho? or just plug it in and see what happens? worried about damaging system. Thanks again Lurcher.

Re: OMC Tachometer and Evinrude 40hp.

Plug it in and see what happens. If the tach doesn't work, neither does your charging system and visa versa.

Re: OMC Tachometer and Evinrude 40hp.

Thank you will post results. Lurcher

Re: OMC Tachometer and Evinrude 40hp.

This engine is 23 years old so one can only assume the tach connection in the control box harness at the engine is in tact provided no repairs have ever been made. If you plug in the tach and it doesn't work, it is not necessarily an indication the charging system is not working. It can be but it not proof positive. If the tach connection in the harness was miswired or simply not connected at the engine the charging system may work just fine -- but the tach may not. You should see +12V and ground at the control box connector with the ignition ON. If the meter shows any movement at all on the pulse line that line is apparently connected and functioning. A voltage check of 13V or higher at the battery with the engine at 1500 - 2000 RPM is proof positive the charging system is working.

Re: OMC Tachometer and Evinrude 40hp.

Many thanks Silvertip for informaton, assuming I get no power at control box with ignition on, where on engine can I check for connection, colour of wire etc, Lurcher

Re: OMC Tachometer and Evinrude 40hp.

+12V and ground are obtained internal to the control box. +12V is via the ignition switch. Ground and the tach line passes from the three-pin connector, into the harness, back to the connector at the engine and from the mating connector on the engine to the terminal block on the engine. If everything looks original at the terminal block (no disconnected wires) check the plug terminals to make sure those are not damaged or corroded. If you have any gauges on the boat that come to life when the ignition is in the RUN position +12V and ground are making their way to the control box. The fact that the engine turns over with the ignition in the START position also indicates you have power and ground at the control box. Absence of +12V and ground at the tach connector would then mean the problem lies in the box. Lack of a tach signal could be due a harness problem or the charging system (fried rectifier). Measure running voltage at the battery. As I mentioned, anything over 13V indicates its functional. But 12.6V or less means the battery is not charging. But that can be due to corroded or bad connections at the solenoid, battery, battery cables at the engine, or the terminal strip, or a bad rectifier.