# Kohler Carburetor Solenoid



## RKDOC (Jun 20, 2006)

I am working on a Kohler CH20 Spec # 64503. Ser # 3330717291. The key switch and wiring were totally corroded off. I replaced the key switch and now am rewiring the switch part of the engine. On the carburetor there is a solenoid that has two wires coming off of it. One is ground and the other power. On the power wire it splits into two wires. Both wires contain a diode. The service manual shows one wire going to the start post on the key switch. The other wire goes to the Battery terminal on the key switch. When wired this way as soon as i connect the battery cable the solenoid is energized (I can hear it click) My question is how does this solenoid work. Wired the way it is the solenoid is energized all the time. Most afterfire solenoids are wired to turn off when the key is off and on when the key is on. The engine starts and runs great wired the way the service manual shows. How does this solenoid work? Thanks for your insight.


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## 30yearTech (Sep 14, 2006)

Look for a terminal on the switch that is hot when the key is in the on position, and open when in the off position. This is the terminal it should be hooked up to. Many times the charging circuit is hooked up through the key switch this way as well.


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## RKDOC (Jun 20, 2006)

Thanks 30 year. I already checked for a terminal that is hot with the switch on not when it is off. there is no such terminal on the switch. The voltage regulator is wired direct to the hot side of the starter solenoid.


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## 30yearTech (Sep 14, 2006)

Are you sure you have the correct switch for the application? What is the brand and model # of the unit the engine is being used on?


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## RKDOC (Jun 20, 2006)

I got the switch from kohler. I looked the part number up on the Kohler Plus web site. On page 8-4 of the ch20 service manual shows the wiring diagram. I was afraid the switch being on all the time would drain the battery. The engine has sat for three days and started with no hesitation. The engine shuts off with no backfire. Thanks for the help.


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## 30yearTech (Sep 14, 2006)

Well it will take quite awhile for the solenoid to drain the battery, but eventually it could if it sat long enough without use. The solenoid is useless in preventing an after fire event if it's energized when the engine is shut down.


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## RKDOC (Jun 20, 2006)

Thanks 30 Year Tech. With my last post I just meant that the solenoid seems to be working properly even though I don't think it is wired right. I know that diodes allow power in one direction and not the other, but could the diodes have something to do with the way the wiring is set up? Just thinking out loud. Thanks


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## 30yearTech (Sep 14, 2006)

Does this engine have Smart Spark?
They usually put the diodes in to prevent feed back to the SAM box from the power to the fuel solenoid. Other then that I can't see any reason for the diodes in circuit to the solenoid.


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## RKDOC (Jun 20, 2006)

This engine does not have smart spark.


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