New One on Me

[acfarmer]

I've been working on various vehicles and equipment for a lot of years but here is a new one for me. Bought a Bolens QT 16 last night at an auction and it has the Onan 16HP like the AC 616 or Simplicity 4040. It wasn't started at the auction so when I went to start it the starter would run but not engage. OK I figured bad bendix no big deal. This Am I started to look at it and the starter was running backwards. Hummm then looked at the battery and it was hooked up backwards switched the battery cables and it started right up. First time I have ever seen a sarter that would reverse by switching the battery cables. BTW great little tractor with hydraulic lift and 3 pt guess I did OK for $140.

[joshuaareed]

very nice, my John Deere 100 will also do that, and both battery cables are black, nice huh.

[ka9bxg]

With dc you can reverse the motor direction by switching the wires. That is how the window motors that people use for shoot rotators work.Bob

[acfarmer]

Most starters will not run backwards by switching polarity.I've changed a bunch of positive ground farm tractors to negative ground and the starters always ran in the same direction before and after the switch.I'd like to know what makes this starter change direction when others won't.

[JJ MARSHALL]

i think it has something to do with the fields inside the starter i think that the kohler starters will do the same instead of field with winding they use magnetic field > magnets<

[Al]

Hi, Starters with field coils don't care which polarity feed they have. When the polarity to the starter is reversed, the current flow through the field is reversed to match the reversed magnetic field in the armature. All starters with permanent magnet fields the magnetic field is always the same and when the voltage to the armature is reversed the magnetic field around it is reversed but the field magnetism is constant and the starter will turn in the opposite direction. Al Eden