Generac corepower 7kw propane.

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Jbspeed79
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I have had this machine for 8 years. I ran it’s weekly checks for years but haven’t really lost power a whole lot to run it on a load. I have replaced choke solenoid and battery and replaced and gapped the spark plug. After sitting for a week the machine has a hard time starting sometimes setting the overcrank error. Once it runs it obviously starts right back up easy. Following the flow chart I tested out the choke solenoid plug. It reads 4.8 volts unplugged and not running. When I go to start the generator the voltage drops into the negative. I don’t think the choke is opening up due to voltage issues. The next step is to replace the controller. Does that sound right?
Chris
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I would certainly look at fuel issues, the fuel regulator vent on the back, the valves, etc. before I start talking controller replacement!
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Jbspeed79
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Thanks. I do notice that the choke does not work or open anytime it’s trying to start. I replaced the choke but it wasn’t that. I hooked a volt meter to the wiring harness and when the engine is stopped it shows 4.3 volts. When I go to crank the engine the voltage goes in the negative. Seams as if the choke isn’t opening because of something. Thanks for the information.
Chris
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If you manually work the choke, does it start?
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rogeru
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Chris wrote:
Tue Sep 28, 2021 8:06 am
I would certainly look at fuel issues, the fuel regulator vent on the back, the valves, etc. before I start talking controller replacement!
I am not familiar with your unit nor a tech. A generator owner. My thoughts though. The DVM reads potential difference. I looked at a wiring diagram. Wire’s 15A and 90 go to the choke solenoid from the controller. I am going to assume 15A is the supply voltage side. If one test lead is on 15A and the other is to ground you should see the voltage the controller is supplying. I believe the choke solenoid is controlled on the ground side by the controller. When the controller grounds wire 90 the coil in the solenoid is energized and it moves. Since the voltage is used up by the part that is doing the work (fuel solenoid) there is no more potential difference so the reading is 0. Based on your result I believe the controller is working. You could disconnect the choke solenoid wires and set your meter to ohms scale and check the choke solenoid. This reading could be compared to your old one as the spec may be difficult to find. There should be some resistance.Does the flow chart tell you what voltage to expect? I would think a cold engine on start up the choke would be in the closed position.
UnknownOverlord
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This time of year, check the little black vent off the fuel regulator. Spiders love to put nests in there.
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Jbspeed79
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Thankyou for all the suggestions. Yes it starts If you manually work the choke.
It has started the last few weekly test cycles. Just cranks a few extra times because the choke isnt working.
I have observed the choke on each of the weekly test cycles and it doesn’t move or (energize). The choke does move freely and just replaced brand new. I’ll check the voltage again and report back. It shows one wire is the voltage wire and the other is the ground wire. When the relay grounds out the ground wire, when cranking, it sends voltage to the choke and closes shut. To me it looks like the correct voltage from the controller is not there to close the choke when cranking. But I could be wrong. Wish it was an easy fix to repair circuit boards than to spend 300 for a new one.
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Jbspeed79
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Here is a video of the voltage of the choke at the controller. Not sure if video can be posted. During cranking the voltage goes positive to 4.5 volts. I unplugged the choke because the voltage acts funny once you plug the choke back in.
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rogeru
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The manual says you should have battery voltage. It should be around 12.6 volts. You are getting 4.5 volts from your test. Check the connector at the controller. Probably 4.5 volts is not enough to operate the solenoid. The resistance of the solenoid should be around 3.7 ohms.
Jbspeed79
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Ya I checked the ohms and it was 3. I made one last ditch effort to spray some electric cleaner on the board itself. I have check all the trouble shooting and agree it must be the circuit board controller. I see they sell them for 299. Nothing seams to last this day in age. Thankyou all for trying.
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