MAkes no sense Mercury Tachometer problem.

[racervboat]

Maybe it needs a harness to hook up everything to work together ?

[Tom Smyth]

As I said this absolutely makes no sense. All good suggestions, but have been tried...... ARRGGHHHHHH

[FMP]

Whatever you haven't replaced in going through it must be responsible if you haven't overlooked something. Can't be some unknown EMP fields , you right against a huge transformer warping space and magnetic fields?

[Mark75H]

Now its time to test continuity. Test brown from stator to tach and ground to tach ground. Probably the ground that is open somewhere.

If the alternator puts out 14+v there is no problem with the stator or magnets, the problem is the wires between the stator and the tach.

[mn808gade]

gotta be a bad wire eyelet or connection-i feel for ya-th

[Steve Pope]

Is this engine a distributor model or a 6 coil. Is the rev counter a 2 wire 60 degree sweep or a 3 wire 270 degree?

[flabum1017]

Have you done a stator wire to ground test? The smallest trace to ground will short out the tach signal

[gfinch]

To do a voltage drop test, you create a load in the circuit that's being tested. Then you use a digital volt meter (DVM) to measure the voltage drop across the live connection while it is under the load.
In my 40+ years as a mechanic, I've had many very strange problems(electrical) thru the years and found their cause with this test.

[Steve Pope]

Is the charging system actually charging the battery?

[Dave S]

No good Merc.... send it to me....might have too many carbs.......

[Tom Smyth]

Took some time to breath and no taking a methodical approach back at it. First stator I am trying measures .6 ohms resistance which is good. on the motor at idle I only measure 11.8 volts DC out of the rectifier at the red lead. With yellow wires disconnected from the rectifier, using a DVA I measure 48-52 AC volts coming out of the stator. that tells me the stator is putting out, but the rectifier has an issue. BTW checked tach wiring and tried it and still no tach... Replacing the rectifier. one thing at a time...

Thoughts??

[XstreamVking]

Rectifier no good, tach won't work? Seems I remember that happening on the IL-6's. Been 35 yrs since I had one......

[Tom Smyth]

yes but trying to find exact info on how to nbench test them is interesting.... everyone has an opinion....
Would ike to find the MERCURY specified resistance measurements fo rthe diodes.