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1975 85hp Johnson choke issue

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GaryOutland

Contributing Member
What is supposed to cause choke solenoid to return to open position once switch is released? I am attaching a picture of what I have.
Thanks, Gary KIMG0193.jpg
 
I looked up part number after Boobie gave it to me. I see that solenoid is listed with intake manifold on this site. I am still learning my way around. This is my first forum. What is NLA?
 
The choke is not supposed to return to the open position when the switch is released on that model. It is supposed to return to partially open warm-up position. That is, until the motor is warmed up. Once warmed up, it opens fully. OK, having said that, there was a service bulletin describing how to modify it so it is either fully open or fully closed according to switch position, eliminating the partially open warm-up position. So, answer to the question is has it been modified?


 

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  • Wiring 1972 Choke modification.jpg
    Wiring 1972 Choke modification.jpg
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There is more than one post on this very fine motor.------------Owner says that " thermo electric " function is bypassed.
 
OK, if that is the case, it should open. If the NLA spring is missing, you can probably find some sort of a substitute at Ace Hardware, or similar store.
 
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Thanks racerone and fdrgator. I will come up with a spring. I assumed that choke was attached to thermal switch to choke out engine in case of overheating. After seeing diagram and reading your responses, I now understand.
Thanks again.
 
Gary.... Here is the info on the modified circuitry:

(Temperature Actuated Choke Solenoid Conversion)
(J. Reeves)


Various OMC engines that were manufactured in the later 1960s thru the early 1970s, for example the 1969 55hp Evinrude/Johnson incorporated a dual stage choke solenoid...... easy to identify as they have two wires leading to the solenoid, one purple/white, one purple/yellow.

The purple/yellow is attached at the engine wiring terminal strip to another purple/yellow wire that led to a heat sensor. The initial stage, with the key ON, (purple/yellow), when cold, would keep the choke pulled in half way until the engine warmed up, at which time it would release and open the choke butterfly.

The second stage (purple/white) is attached to another purple/white wire at the engine terminal strip which leads to the choke switch. When the switch was engaged, the choke closed etc.

The problem with this setup is that as the engine got older, the thermostat acted up, water pump became weak, whatever, the heat sensor failed to operate properly and the choke would not release from that half closed position. This would cause the engine to run in a rich fuel mixture condition (flooding, loading up).

The cure to this problem, via a service bulletin from OMC was to remove the solenoid purple/yellow wire from its original location and connect both of the solenoid wires (purple/yellow & purple/white) to the engine wiring harness purple/white wire at the engine terminal strip.

The above change would allow both solenoid wires to be energized when the choke switch is engaged, pulling the choke butterfly in firmly..... and only when the choke switch is engaged.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1


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I also have a couple of those 314026 choke springs left in my remaining stock, new of course... $15ea includes shipping if in the states.
 
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