Re: [OMC-Boats] OMC FACTORY SHIFTER DIAGNOSTICS

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

----- Original Message -----
From: "jd" <jdood@...>
To: "Evinrude & Johnson Boats of the 1960's and 70's"
<omc-boats@...>
Sent: Monday, August 24, 2009 12:06 AM
Subject: Re: [OMC-Boats] OMC FACTORY SHIFTER DIAGNOSTICS

>
> On Aug 23, 2009, at 8:40 AM, Lee Shuster wrote:
>
>>
>>
>>
>> ===========================
>>
>> Jeff and others reading this list: Please review the factory diagram
>> I've posted here:
>> http://hhscott.com/evinrude/images/wiring/68_v6_ALL_WIRE.jpg
>>
>> Sorry for the "preachy" attitude here, but personally, I would NOT
>> recommend "jerry-rigging" ANY type of alternative electric shift
>> controls or "make-shift" alternative toggle switches for the purpose of
>> operating the electric shift coils. It's UNSAFE and you risk destroying
>> your engine and drive. Just not worth it for an extra weekend or three
>> at the end of the season.
>
> well, had i checked my email before leaving my house this AM I might
> not have, but I ended up installing a toggle and took it out for a test.
> Yes it's a little weird, but it went ok. I get what you're saying -
> not safe and risky to engine - but I need to drill down on those two
> things so i fully understand the stakes here.
>
> SAFETY: Is the main issue is that the engine can accidentally be started
> while in F or R right? Or is there another safety concern? Because
> with a 3 wire switch, I would still have that same safety issue.
> What's the difference?
>
> MECHANICAL RISK: Is it the risk of accidentally switching while
> underway? Tripping the switch at too high RPM? If so, makes
> sense. But If the factory switch was working / installed properly and I
> moved the shift lever from forward to neutral to reverse - what happens
> with the engine RPM when it goes into neutral for that second or two?
> What's the "safe" max RPM to shift around?
>
> Am I forgetting something - or are those the two main concerns? I
> absolutely don't want to damage my engine. I'm fine with launching
> myself out of the seat through the windshield and into the water by
> accidentally changing gears at high speed, but I'm not fine with
> damaging my engine.
>
>
>> Take the time and do it right. If you don't want to spend the big bucks
>> on a third-party switch for your single-lever Johnson/OMC control, then
>> I would recommend a used Evinrude push-button remote control. I've never
>> head of a switch failure in those units. (The sliding mechanical window
>> or aperture can slip out of adjustment - but any resourceful Captain
>> with Phillips driver can fix that - just ask BC (see his page/photos on
>> the OMC boat web)
>>
>> BTW, Jeff from your "difficult-for-me-to-decipher" troubleshooting
>> description, I think you have a possibly, of having incorrectly
>> installed the switch (mechanically) in the remote control housing (see
>> "red" above).
>
> That was 1/2 the problem with the new switch. Just as the manual says,
> the little roller was slipping out of the slot. Quite a challenge
> seeing that happening when everything is closed up and hidden in the
> housing. Used my xray vision.. The other 1/2 of the problem i guess
> i didn't explain well enough was that even when I was holding the switch
> in my hand and testing it with the light, it only lit up in neutral and
> reverse positions. Not forward.
>
>
>>
>> Lee
>>
>>
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Received on Monday, 24 August 2009