Onan Generator 4000

Droptop351 wrote:
Had this exact problem this week. All of the answers above could be correct, low voltage, bad solenoid or starter, bad cable connections.

Mine was stupid thing turned off on compression stroke so I took a 9/16 wrench and turned flywheel and loosened it up. Started right up

If you want to rule this out take the spark plug out and hit the start button if it don't turn over and just clicks then it's one of the 3 listed above

Most small engines will come to a stop at the compression stroke, since that's where the friction/force is greatest in stopping the flywheel's rotation. The starter should be able to kick it over the compression stroke without trouble; if it can't, then either there's a bad connection or battery (so it's not getting full power) or the starter is at least partly faulty.

I had a starter that was barely able, on a good day, to overcome the first compression stroke. I eventually burned it out trying to start it on a not so good day. Upon inspection after replacement, I discovered that one of the four brushes had become disconnected, which explained the initial low starting power, as well as having one or two of the coils burned out (the final death blow).

These starters, unlike many electric motors, have four brushes and hence two pairs of magnetic poles around the rotor. If one of the four brushes is not making connection, it will still turn, just at half power. Unfortunately for people like me who need to replace the starter, it's located on the back side of the engine and is not accessible without dropping the generator and removing the outer cover entirely (not just the maintenance hatch), which makes it a rather laborious task to get to the point of replacement.