Choke Solenoid OMC 1994 Wiring

Electrical and electronic topics for small boats
dirk2005gto
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Choke Solenoid OMC 1994 Wiring

Postby dirk2005gto » Mon Nov 19, 2018 11:17 am

[This thread has been moved to SMALL BOAT ELETRICAL for discussion of the electrical wiring.--jimh]

[My1994 Evinrude 200-HP engine] always had a hard time starting using the choke. I replaced the valve and gaskets on the choke solenoid. I also checked [resistance]. I gave [the solenoid] 12-Volts to see how the solenoid works. It all checks out.

[Should there] be 12-Volts on the violet wire with the key pushed in and not turned?

Or must you push and turn the key to receive 12-Volts?

Sometime I hear a beep and sometimes I don't hear a beep when I turn the key.

BACKGROUND:In the process of cleaning everything on the engine and winterizing my 1994 21 Outrage, I have replaced all the floats and gaskets in the carburetors of the 1994 Evinrude 200. I removed the throttle body and cleaned and replaced all the gaskets too.

If I manually turn the valve [on the solenoid assembly the engine] starts without a problem.

[The 1994 Evinrude 200-HP engine] began to spit and cough and die toward the end of the season during idle. I decided to rebuild all the carburetors.

Strangely, if you raised the idle via throttle, [the engine runs] fine, [the boat] goes up to 40-MPH without a hiccup.

I checked the [peak pressure] on all the cylinders and they were all between 110 to 114-PSI.

jimh
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Re: Choke Solenoid Circuitry

Postby jimh » Wed Nov 21, 2018 10:23 am

For help understanding the ignition switch circuits see

http://continuouswave.com/whaler/refere ... witch.html

You seem confused about which conductor is associated with the solenoid circuit. The solenoid is operated by a conductor with insulation color violet with white stripe.

jimh
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Re: Choke Solenoid OMC 1994 Wiring

Postby jimh » Sun Nov 25, 2018 10:32 am

dirk2005gto wrote:Sometime I hear a beep and sometimes I don't hear a beep when I turn the key.


For advice on interpreting the aural alert sounds from the outboard engine, consult the operating guide for the engine. The operating guide will explain the aural alert sounds. Generally the cadence, duration, and time of occurrence must be used to interpret the meaning of the aural alert sound. An aural alert sound that occurs immediately after moving the ignition key switch to ON from OFF usually is just a confirmation BEEP to indicate initialization of the alarm system.

In any alarm system, when an alarm occurs there are three possibilities:

--there is a malfunction, the alarm system has detected the malfunction, and it is giving a proper signal;

--there is no malfunction, but a sensor is bad, signaling a false alarm; or,

--there is no malfunction, all sensors are good, but the alarm system itself is malfunctioning.

Use these possible situations as your guide to diagnosis of the cause of the intermittent alarm signal that occurs when you move the ignition key switch to ON from OFF.

dirk2005gto
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Re: Choke Solenoid OMC 1994 Wiring

Postby dirk2005gto » Sun Nov 25, 2018 12:07 pm

Hi Jim, I understand the meaning of the various beeping alarm sounds and type and duration. Those alarms are explained on a decal near the throttle shifter. The single beeps I was talking about is usually made when the key is first inserted into the ignition key switch and turned [to ONN] but not to the start position. Sometimes I hear it sometimes I don’t.

Is that single beep supposed to sound at every startup?

It is akin to the chime when we insert the car key into the ignition. Thanks for the guidance.

jimh
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Re: Choke Solenoid OMC 1994 Wiring

Postby jimh » Sun Nov 25, 2018 2:29 pm

dirk2005gto wrote:Is that single beep supposed to sound at every startup?


If you have the MWS harness and the System Check tachometer, the aural alert sounder is operated by the System Check tachometer. That device might trigger the aural alert at power-on. I don't recall if it does. If the System Check does trigger a short BEEP on power-on, it should do it every time, not just on an intermittent basis.

If you don't have the MWS harness and just have a conventional tachometer with the aural alert sounder operated from the wiring harness, any signal to sound the aural alert would come from the engine.

Here is some background on the differences between the older rigging and the newer MWS and System Check rigging.

In the original configuration there are four sensors which can trigger an alarm. The sensors are:

--oil reservoir level float switch

--cylinder head temperature-sensitive switch

--fuel line vacuum switch

--OMS ("VRO2") pump flow sensor

In the original configuration, all of these sensors were connected in parallel in a wired-OR configuration to the TAN alarm wire. If any sensor detected a fault condition it would pull the TAN alarm wire to ground. This would cause the aural alarm sounder to operate, alerting the operator of the fault condition.

Because all the sensors were wired parallel, you could not distinguish which one was triggering the alarm, except by interpretation of the alarm cadence or the circumstances of the alarm.

In the new configuration, the four alarm sensors are kept separate. Much of the electrical modification consists of re-wiring the various sensors with new wire and new connectors. The TAN wire is now changed to TAN plus a color identification stripe for each sensor. Instead of one TAN wire to the helm there are four TAN-plus-color-stripe wires.

The four alarm wires connect to the SystemCheck gauge. When an individual alarm sensor indicates a fault condition, the SystemCheck gauge identifies which sensor is signaling.

The aural alert is also changed. In the old configuration the aural alert was supplied with battery voltage and the common TAN alarm conductor turned on the alert when it was grounded. The new aural alert is driven from the SystemCheck gauge. The SystemCheck gauge tells the aural alert to sound and controls the cadence.

In the new system (MWS) I am not certain if the aural alarm has a distinct cadence for each alarm or not. I only had the alarm go off once, and that was for the low oil reservoir level (and it was intentionally done to check that the level sensor was working). The alarm gave an alert for about 30-seconds, then it changed its cadence and went to a staccato chirp once every ten seconds or so.

If you have the older wiring, you can investigate which sensor is triggering the aural alert by temporarily disconnecting them, one at a time, and testing to see if the intermittent beep at power-on ceases.

dtmackey
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Re: Choke Solenoid OMC 1994 Wiring

Postby dtmackey » Sun Nov 25, 2018 9:32 pm

dirk2005gto wrote:[Should there] be 12-Volts on the violet wire with the key pushed in and not turned?


The fuel enrichment solenoid receives 12V when the key is on and you push the key inward. I find it works best if you turn the key on, push in for 2 seconds and then turn the key with the key held in until the engine fires, then you can give it a little push if it starts running rough or tries to die.

Dangar Marine does a great job explaining in this vid. He also has many other self-help vids that are a good resource.

https://www.youtube.com/watch?v=BrBj2p4A8xQ

D-

jimh
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Re: Choke Solenoid OMC 1994 Wiring

Postby jimh » Mon Nov 26, 2018 12:51 pm

The instructional recording linked above is very informative and well done.

It omits one common problem. The problem occurs when at end-of-season a fogging oil aerosol container is connected by a hose fitting to the Schrader valve on the fuel enrichment assembly. After the fogging oil has been induced into a running engine, the process of unthreading the hose and fitting from the Schrader valve will tend to rotate the valve assembly into the open position. The next time the engine is started, in the Spring of the following year typically, the fuel enrichment valve will be in the open position, and the engine will be getting continuous fuel enrichment. Running on overly-rich fuel-air mixture will cause the engine to stall at idle speeds and run poorly if it runs at all. The manual valve must be closed to prevent this.

As an indicator of how commonly this problem occurs, I experienced this exact problem the first time I used the aerosol fogging oil with the Schrader valve fitting attachment. I got to the launch ramp, and could not get the engine to start and stay running. It was a warm Spring day. Dozens of other boaters were behind me in a long line at the launch ramp, so I pulled the boat back on the trailer and gave up.

I called my Evinrude dealer, Lockeman's Boat and Hardware the next day (Monday), and told Dave, the owner and an expert OMC technician, what had happened. He immediately knew the cause. He told me to remove the engine cowling and check the position of the red handle on the fuel enrichment assembly. Of course, the valve was open. Dave said he gets calls about this problem every Spring from customers who did their own engine winterization. Since Lockeman's is probably the most honest outboard repair shop in North America, they just tell their customers how to fix this problem over the telephone, instead of having them bring the boat to their shop for a service call.

dirk2005gto
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Re: Choke Solenoid OMC 1994 Wiring

Postby dirk2005gto » Mon Nov 26, 2018 9:56 pm

I think my lack of hands on experience caused me to run into these problems. After doing some more reading, I think the root cause of my hard starting is ME. For the first time yesterday, i followed (what i think is) the proper starting instruction for my boat. Insert key, turn to the ON-position, it beeped. Waiting three seconds, turned the key while pushing the key. The engine fired right up after sitting for a week. I released the key once she fired, pushed the key in two more times to give a little more fuel, and she cycled thru the cold start.

This is my first boat. I bought it last November, and I still have a lot of learning to do. The original owner i bought the boat from was 82-years-old and simply couldn't handled the boat anymore. He was sad to sell the boat, but knew it was time. I have all the documentation and read thru most of them now. I really didn't do much since i bought the boat last year besides changing the water pump, fogging it, and changing the lower unit oil before I stored it last year. I put it in the water this spring, and ai ran it as-is until the idling problem started to occur after running thru 150-gallons of fuel.

I also believe the carburetors really need that cleaning, and removing all the carburetors and throttle body, cleaning them with carb cleaner, using different gauge guitar strings, running them thru all the tiny carb and throttle body ports, and finally blowing it out with the compressor really did the job. I also removed the primer solenoid and replaced the gasket, cleaned the fuel screen inside and finally tested the resistance to make sure it is in good working order.

I did run into the hard start problem Jim described during the first startup this spring. I did exactly what Jim did. I fogged the motor thru the primer solenoid till she stalled and then on top of that, i took all the plugs out and sprayed more fogging oil into the combustion chamber while turning the motor by the impeller. But I did pull the plugs after she failed to start and just sprayed brake cleaner on the plugs; she fired right up because they were fouled by the excessive fogging oil. It might help u in the future to clean the plugs with brake cleaner if she fails to fire.

Jim--thanks for all the help and diagrams.

jimh
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Re: Choke Solenoid OMC 1994 Wiring

Postby jimh » Tue Nov 27, 2018 9:27 am

I had a similar engine, a 1992 Evinrude V6. Following the exact procedure for starting was always the best way to start the engine. Using the manufacturer's recommended starting procedure always produced easy starts for my engine. I was impressed with how well it worked, and it was never a problem to get it running.

Also, if you encounter any unusual persistent fast-idle speed after the engine comes up to operating temperature, look for the temperature sensor lead to have fallen off the temperature sensor.

Another long-term component to watch carefully: the OMS mixing pump. Read about them at

VRO STORY—The Myth of the Mixer
by Bill Grannis

http://continuouswave.com/whaler/reference/VRO.html

I believe the OMS pump is still available as a replacement part. It has gotten a bit expensive, probably about $400 or more. But with modern fuel having a lot of ethanol, the pump can fail. My 1992 engine got a new OMS pump about c.2012 at age 20-years-old.