Re: [OMC-Boats] OMC Shifter Switch Stuff (more)

I have a 1988 edition and suspected it could be wrong, thus the "I wouldn't
trust it" comment. That said, it seems like it would be fairly easy to wire
your own interlock: Wire up a normally closed solenoid such that if either
of the drive clutches is engaged, it breaks the power circuit to the starter
solenoid. When in neutral there would be no power to the drive clutches or
the "interlock solenoid" and thus the normally closed status would allow
normal starting.

I have one of those non-shifting outboards! Mine is a small, c. 1970 4.5 Hp
"Ted Williams" outboard I use on my "beach boat" (the rowboat I leave on the
beach for those emergency fishing attacks). Mine is a bit more
sophisticated though, I can swivel the powerhead 180 degrees to get reverse.
I like it because it is very lightweight and easy to carry up and down the
stairs. Of course its a lot smaller than the "Tower of Power," but my Dad
had a similar higher output model (probably an I4, but I don't know for
sure) from ~20 years earlier. After he died I found copies of some drawings
and a letter he had sent to one of the manufacturers (forget which)
"encouraging" them to add a transmission by showing them how to do it.

Andy

----- Original Message -----
From: "Lee Shuster" <Lee.Shuster@...>
To: <omc-boats@...>
Sent: Monday, August 24, 2009 4:09 PM
Subject: [OMC-Boats] OMC Shifter Switch Stuff (more)

> Depending on the edition of your Seloc manual (most were written after
> 1969) the N-S starter inerlock (5-wire) probably doesn't exist on most OMC
> owner's boats on this list. This feature didn't appear on any OMC remote
> shifters until the 1969 model year. So most of have the 3-wire
> (non-interlocked) setup which will allow for rather interesting,
> FULL-THROTTLE, IN-GEAR (FORWARD or REVERSE) dock-busting starts, if you
> aren't paying close attention.
>
> At least OMC engineers didn't copy the Big Mercury, Karl Kiekhaeffer,
> outboards of the late fifties. They had FIXED-drive, lower gear cases
> which had NO neutral or reverse or shifting ability. You had to shut-down
> the engine for neutral.
> The engine had a bi-directional starter motor for reverse!
>
> This was done so they could handle the additional torque of the first
> "Tower of Power" inline 6 cylinder outboards, without designing a
> higher-torque, F-N-R gearcase.
>
> Elegant, fast, cost-efficient "Quicksilver" engineering or foolish
> blunder -- you decide!
>
> Not the way OMC would engineer it!
>
> Lee
>
>
> On Aug 23, 2009, at 11:38 PM, Andy Perakes wrote:
>
> The Seloc manual says "a cutout switch prevents the starter from being
> energized except when the shifter is in the neutral position" so there
> shouldn't be a safety issue, but I wouldn't trust it on those words alone.
> One of the manuals I read (I forget which) also says not to turn the prop
> with the ignition on and either clutch engaged due to risk of starting the
> engine (I'd be really surprised if you could crank the engine by the prop,
> but maybe they envisioned selling to the bionic man).
>
> Anytime you need to synchronize the speeds of two driveline components,
> you want to do it with as little energy as possible. Near as I can tell
> from messing around with my shifter, as soon as you shift off neutral, the
> coil is energized before the engine starts to rev. There's actually quite
> a lot of motion required on my shifter before the engine revs pick up --
> more than enough time for the speedy electrons to do their thing before
> the fuel and air can catch up in the cylinders. Thus if you shifted from
> forward to reverse before the engine had time to wind down, I suspect you
> would indeed cause damage. Likewise, if you rev the engine then shift
> (analogous to a "neutral slam" on a car), you most likely will break
> things. This isn't unique to our boats -- any clutch has a power limit
> and can be broken. Impact loading causes many thousands of times more
> damage than normal running loads so even if it didn't break the 1st time,
> it would be the equivalent of 1000s of hours of normal operation in terms
> of lifetime damage accumulation. I would always try to shift at idle,
> definitely never above 1000 rpm.
>
> Andy
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Received on Monday, 24 August 2009