27kw getting over crank error light instead of exercise cycle

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Genitup
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so I have 27KW S/N 5092763 mfg 8/2008 running on natural.

Two weeks ago instead of the exercise cycle running I got the over crank light come come. (in this state I forced a utility outage and Genset would not start).
I do not know if the starter motor ran to attempt exercise cycle.
I was able to clear the error and manually start the generator and it ran/switched fine. Auto start on utility failure also worked fine.
I took note of this and prayed (knowing full well something was up)
last week the generator ran its normal exercise cycle fine.(wonderful, problem fixed itself)
This week I got the same error, over crank..(reality sets in)
have you heard of this problem?
Chris
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Overcrank means the unit attempted to start several times and didn't. Fuel would be the first place to start!
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Genitup
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make sense, I will go listen to the next attempt, reading the manual sounds like it will try six times before illuminating error light.
The only thing that bothers me on this is there is no problem starting it manually, fires right up...
any way to force an exercise cycle so I don't have to wait another week?
Chris
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Well, if you set the exercise, that would basically be the same thing. It runs during the setting process.
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Genitup
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I have an update on this:
first of all it is not an over crank error light it's an over speed error light that flashes, but the engine never runs its exercise cycle

So for the exercise cycle that was supposed to run today I went out to the generator and watched and listened to what it actually did, and at the prescribed time the starter motor kicked in and started to turn over the engine for about 1 or 1.5 seconds, engine did not start then it sounded like the solenoid for the starter motor couldn't keep the starter motor gear engaged and the starter motor just spun freely for 2 to 3 seconds, then the over speed error light came on and flashed, and game over. What's strange is that I hit manual start right after that and engine started and ran just fine?
Battery is seven months old and floating at about 13.5 V, starter motor sounds healthy and strong, like it always has (except when I got the condition as above)
thoughts?
Chris
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I would take a look at the mag pickup. That's a classic sign that it's failing, misadjusted, or has metal debris stuck to the end pin.
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Genitup
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will do, adjustment procedures in the manual?
Chris
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Unfortunately no, they won't be in the owner's manual. You should check resistance of the sensor itself first. It should be about 1000 ohms or so.

The adjustment is fairly straight forward. Pull the sensor out, center a flywheel tooth in the hole and then screw down the sensor until it just touches the tooth, back it out 1.5 turns and lock it down.

The new rpm sensor is here if you need one: https://shop.gentekpower.com/products/g ... uid-cooled
Generac tech for over 12 years. I'm here to help!
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Genitup
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Thought I would circle back and let you know the Fix.
checked mag pickup and was clean and 950 ohms.
Turns out it was the starter motor/solinoid.
1 out of 10 start attempts it would crank for about 1 second then solinoid could not keep gear engaged with flywheel and starter motor would spin free for about 3 seconds then get overspeed error.
So I think they should call that an underspeed/overspeed error.
I proved this by disconnecting batt from starter motor but keeping connected to gen set and R-200B. then tried to start and solinoid engaged but no motor spin and it gave overspeed error.
Genset is 12 years old but probably has no more than 1000 starts, which isnt much if you compare to a car that could have that many starts in 1 year.. so I ask is this a common problem with these starters?
I hope this helps someone else
Chris
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I appreciate the follow up! No, I would not say it's terribly common, however I have seen it, on a 60kW actually with the same 2.4L engine. I have a bunch out there though and they seem pretty reliable.

That starter is here if you need it: https://shop.gentekpower.com/products/g ... rter-motor
Generac tech for over 12 years. I'm here to help!
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