How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Curtis B. Your Own Question
Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 12726
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
30244710
Type Your Small Engine Question Here...
Curtis B. is online now
A new question is answered every 9 seconds

My 13KW GENERAC NG generator tries to start, but goes into

Customer Question

My 13KW GENERAC NG generator tries to start, but goes into "over crank". I replaced the plugs, but no difference. I hear a solenoid humming somewhere when the unit shuts down. Just seems like it is not getting enough NG. The unit has been running fine for 3 years. Any help would be appreciated. Thanks.
Submitted: 2 months ago.
Category: Small Engine
Customer: replied 2 months ago.
Also checked the choke and it was operating freely. Air cleaner is OK.
Expert:  Hank F. replied 2 months ago.

What are the model and serial numbers?

Customer: replied 2 months ago.
Model(###) ###-####Serial (###) ###-####
Expert:  Hank F. replied 2 months ago.

This is a NEXUS unit. It is a bit complicated to troubleshoot.

The first thing I need to know is exactly what happens when you set the switch to MANUAL. How many crank cycles? How long is the pause between crank cycles? Does the unit just crank and not fire? Does it just fire once or twice and then stop? Does it actually start for a bit (how long) and then shut down?

Customer: replied 2 months ago.
Hank, thanks for your response. On further investigation, I believe I traced the trouble to the throttle stepper motor. Moving it by hand to approx. center position allows the engine to start in the manual switch position and run normally. Moving it to the closed position, turning off the manual switch and restarting, it will not restart from that position.
Expert:  Hank F. replied 2 months ago.

Set the switch to OFF.

Manually move the stepper motor to the full closed position.

Set the switch to MANUAL, and note any movement of the stepper.

Set the switch to OFF.

Manually move the stepper motor to the full open position.

Set the switch to MANUAL, and note any movement of the stepper.

What happens?