Evinrude 25hp Big Twin Model 25018 “The Evil One”

[frankr]

So I still have the same problem – This model (25018) is not supposed to have electric start but it does.

This reply was modified 51 minutes ago by Shamus.

Obviously somebody added the starter to a 25018 manual-start motor

[Shamus]

Thanks for your info, FrankR. Since you mentioned the mercury switch which was also a throttle control, apparently this 25018 does not have one. It seems like a good idea to install one. Are they available in either the old mercury style or in a new form? Since this unusual 25018 has the electric start, and I’m going to wire it to the boat, could I not use the wiring diagram you provided (thank you) and wire it in, and ignore the leads for the choke solenoid and choke switch? Thanks for your patience.

[frankr]

The sole purpose of the mercury switch (on 1955 models) was to prevent operation of the electric starter at high throttle settings. Consider this possible scenario:.. You are cruising along at full throttle, and suddenly the motor quits because you ran out of gas. After a brief panic, you realize it is out of gas and connect your second gas tank, pump it up, and hit the starter button. The boat takes off at full throttle and maybe runs over something or somebody—or worse, tosses you out of the boat. Why??? Because when it ran out of gas and quit running, you didn’t think to retard the throttle and shift into neutral. So you started it in forward gear and full throttle. The mercury switch prevents that by disabling the starter till you retard the throttle (but it will still start in gear–at slow throttle setting)

As for the choke and associated wires, of course you can eliminate that—you will just have to use the manual choke knob to cold-start it.

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Shamus

[Shamus]

frankr wrote:

The sole purpose of the mercury switch (on 1955 models) was to prevent operation of the electric starter at high throttle settings. Consider this possible scenario:.. You are cruising along at full throttle, and suddenly the motor quits because you ran out of gas. After a brief panic, you realize it is out of gas and connect your second gas tank, pump it up, and hit the starter button. The boat takes off at full throttle and maybe runs over something or somebody—or worse, tosses you out of the boat. Why??? Because when it ran out of gas and quit running, you didn’t think to retard the throttle and shift into neutral. So you started it in forward gear and full throttle. The mercury switch prevents that by disabling the starter till you retard the throttle (but it will still start in gear–at slow throttle setting)

As for the choke and associated wires, of course you can eliminate that—you will just have to use the manual choke knob to cold-start it.

So are these switches still available? I’d like to install one.

[frankr]

Part number 376323.. They are out there, wherever you find them.

P.S. If you install one, be sure your wiring is correct. They can be destroyed in a flash if too much voltage is applied.

• This reply was modified 3 years, 8 months ago by frankr.

[Nicholas Keller]

A simple solution would be a micro switch set on shift linkage to only allow operation of starter in neutral

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Shamus

[Shamus]

Thanks, Nicholas. When you refer to a micro switch, is there a particular model you have in mind? I don’t suppose you would have a wiring diagram at hand?

[Shamus]

Thanks for your very informative answer. I’m learning as I go – prior to working on this runabout my boat experience was limited to kayaks and canoes. This boat indeed needs a short shaft – its Transom to keel measurement is about 15 1/2 to 16″. It was my inexperience and convenience (the motor was sold by a neighbor) that led me to get the long shaft. What would be the commonality among other Evinrude 25 hp motors of that era for such parts as the standard shaft? I have a second motor, a 51-53 25 hp manual start motor Big Twin. If I acquired the standard shaft, what could I expect in complexity in swapping them out?

[Shamus]

Again, thanks. Again, forgive my ignorance, but what does the term “split the block” refer to? Is it the entire removal of the powerhead from the engine to get at the shaft?

[Bob Wight]

Splitting the block refers to separating the 2 crankcase halves to get at the engine internals.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

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Shamus

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