[OMC-Boats] Fw: Reverse works great, but...

Sending again without picture....
----- Original Message -----
From: <lib1@...>
To: "Evinrude & Johnson Boats of the 1960's and 70's"
<omc-boats@...>
Sent: Sunday, July 06, 2008 9:04 AM
Subject: Re: [OMC-Boats] Reverse works great, but...

> Hi Micha,
>
> Good in-the-field, logical troubleshooting on your part.
>
> Here's your next step -- You'll need an ohm-meter that can measure
> resistance in ohms.
>
> The shifting is accomplished with electromagnetic "stationary"coils (one
> each forward and reverse) as well as clutch springs (again one each
> forward
> and reverse). When energized with +12 v dc current the coil/spring
> combination causes the driven gear to engage in either forward or reverse.
>
> Basically four elements have to be present or available for shifting to
> occur:
>
> 1) Complete Positive Circuit path for Forward and Reverse (thru internal
> down-leg harness LIGHT-BLUE = FORWARD, LIGHT-GREEN = REVERSE)
>
> 2) There must also be a COMMON return GROUND PATH BACK THRU the down-leg
> and
> thru the intermediate housing. OMC offered a ground-strap kit, but since
> you
> have current flow on the reverse circuit this path is NOT likely your
> problem. But check the resistance bewteen the downleg and the engine
> anyway.
> Should be essentially close to zero ohms.
>
> 3) Each staionary coil should draw approximately 2.25 Amps at 12 v dc.
> Using Ohms law this is easy to measure with a static resistance
> measurement.
> First locate a decent ground point on the down leg and place on probe of
> the
> ohmeter there. The second probe should go to the LIGHT-BLUE or LIGHT GREEN
> stern drive terminal with the remote control disconnected. Your ohmmeter
> should read approximately 12.00 / 2.25 = 5.3 ohms, which you can round off
> to 4 to 8 ohms. (An open circuit would yield very high resistance -- A
> broken or high resistance connection in the wiring would cause this, as
> would an open staionary coil.)
>
> 4) If all the electrical checks prove OK, then you have a defective clutch
> spring. These have a tendency to fail (physically break) when shifted from
> neutral into gear above the recommended idle RPM speed (typically 550 to
> 650
> RPM).
>
> If I had to guess -- you'll find the problem in either step 1 or 4.
>
> I'm writing this from memory, so any one elese feel free to jump in.
>
> Oh, here's a decent picture to better understand what's inside the
> gearcase:
>
>
>
> Also see:
> http://hhscott.com/evinrude/omc_stringer.htm
>
> Lee Shuster
>
> Salt Lake City
>
>
>
> ----- Original Message -----
> From: "Micah Donahue" <mdonahue@...>
> To: <omc-boats@...>
> Sent: Sunday, July 06, 2008 6:27 AM
> Subject: [OMC-Boats] Reverse works great, but...
>
>
>> ...it's tough to pull a skier in that direction.
>>
>> We had our '68 Sportsman 155 in the water yesterday for a sea trial.
>> Started and ran flawlessly, and shifted fine into reverse to back away
>> from the dock. But it wouldn't shift into forward gear.
>>
>> We ruled out the console push-button switches by reversing the 2 wires
>> where they connect to the wires that go into the intermediate housing
>> of the outdrive. Then, as you'd expect, it shifted into reverse by
>> pushing the *forward* shift button. But from that point, we got
>> nowhere. We assume the problem is either:
>> a) a break in the "forward" wire somewhere in the run from engine
>> compartment to lower unit
>> b) bad shift solenoid (assuming that's what you'd call the part that
>> does the shifting)
>>
>> Obviously, next step is to dive in w/ the manual and start looking for
>> wiring problems as the wiring goes from engine compartment to lower
>> unit. Then check the operation of the solenoid. As we do that, any
>> suggestions? Any "duhh" solutions we're missing? Thanks in advance.
>>
>> -Micah
>>
>>
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>
Received on Sunday, 6 July 2008