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: 26044
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 Onan Cummins generator seems locked up won't start so I

Customer Question

My Onan Cummins generator seems locked up won't start so I pulled the starter off and the starter spins fine when I hit the button what could the problem be
Submitted: 1 month ago.
Category: Small Engine
Expert:  Curtis B. replied 1 month ago.

Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!

Expert:  Curtis B. replied 1 month ago.

Will the engine turn if you use wrench on it? If not remove spark plug and see if piston may have fluid on top of the piston.? If it does, spin the engine with spark plug removed to clear the cylinder, re-install the spark plug and see if engine will start?

Customer: replied 1 month ago.
Not really use to working on stuff like this I work on dirt race cars lol where can I put a wrench on it and try at
Expert:  Curtis B. replied 1 month ago.

You have starter off? Just use the ring gear on the flywheel to turn the engine using screwdriver to turn flywheel.

Customer: replied 1 month ago.
Ok motor is not locked up just won't start with starter
Customer: replied 1 month ago.
Starter spins when I take it off but will not when I bolt it up
Expert:  Curtis B. replied 1 month ago.

So engine will turn 360 degrees, and starter works when removed? But will not spin engine if stater is installed and spark plug is removed? Do you ave a voltmeter to test battery voltage? Has to be 12,5 before start and not drop below 8 volts when starter is selected.

Customer: replied 1 month ago.
Ok starter on with spark plug out will still not spin but spins when off and flywheel on motor turns 360 degrees with screwdriver
Expert:  Curtis B. replied 1 month ago.

What is battery voltage when you engage starter? Less than 8 volts, battery or cable problem. over 8 volts, starter or cables! I'm thinking battery problem. Does not have enough amps to crank loaded engine.

Customer: replied 1 month ago.
Dumb question what do I set on meter to for a battery
Expert:  Curtis B. replied 1 month ago.

DC volts, which will be straight line diagram. Red lead on positive and black lead on negative battery terminal.

Customer: replied 1 month ago.
12.5 volts and 10 volts when I hit switch
Expert:  Curtis B. replied 1 month ago.

So battery test good. I think you need a new starter!

Customer: replied 1 month ago.
10-4 will get one Tommorow and try that and get back with you!
Expert:  Curtis B. replied 1 month ago.

OK>

Customer: replied 1 month ago.
Put new starter on still nothing so I tried spinning flywheel again both ways and it spins almost 360 degrees and locks up on the last little bit in both directions
Expert:  Curtis B. replied 1 month ago.

Did you try it with the spark plugs removed?

Customer: replied 1 month ago.
does same thing and everything looks fine spark plug looks new also
Expert:  Curtis B. replied 1 month ago.

But engine does not turn full circle? Has to be a reason engine is locked. I'm thinking you may have a valve stuck open.