Starter motor spins backwards

[eurolarva]

Just rebuilt a starter motor for a 1988 Merc 25XD. Serial number A702838. Replaced the end cap, springs and brushes. I installed it and hit the start switch and the starter motor spins backwards. If I hand turn it in the correct direction it will go up the bendix and attach itself to the flywheel. This starter has one screw on the bottom that goes to a positive 12 volts from solenoid. This is connected to one of the brushes that is isolated from the chasis. The ground contact is made by the two screws holding it to the motor where there is no wire. I used a meter and verified that I have the minus black lead of the battery going to the chasis and the positive lead of the battery going to the solenoid. Any Ideas why this is spinning the wrong direction?

 

[Trent]

Re: Starter motor spins backwards

You need to swap your wiring around on the brushes.

 

[rodbolt]

Re: Starter motor spins backwards

hello<br /> did ya double check your batter cables at the battery?<br />good luck and keep posting

 

[eurolarva]

Re: Starter motor spins backwards

Checked polarity on battery and that is good. Red meter lead to solenoid and black lead to motor chasis is +12.65 vdc. I dont see how I can change polarity to the brushes. This starter only has one place to hook up positive voltage. Ground is done by hooking it to the motor to create a surface ground. One brush is removable by taking it off the mounting screw but the other one is hard wired to the end cap which is grounded.

 

[JB]

Re: Starter motor spins backwards

Starter motors are series wound.<br /><br />To reverse direction you must reverse the connection of the brushes, as trent advises.

 

[eurolarva]

Re: Starter motor spins backwards

Brushes cant be reversed because they are hard wired. Found the problem though. the armature was installed into the motor housing upside down. This caused the north and south to be reversed. We now have it spinning the right way. Just having troubles getting it to go up the bendix now. This is my neighboors motor and I am just helping. Glad I own a chrysler. Does anyone know if the model number stenciled on starter motor is suppose to face out so you can read it from inside the boat? We had it in one way and it traveled up the bendix but you could see it was not in right. Putting it in the other way fit nice but wont go up the bendix

 

[eurolarva]

Re: Starter motor spins backwards

Got the starter all squared away. Had to turn the mounting brackets 180 degrees to make the gear on starter line up correctly on the flywheel. I did a search on this spinning backwards and was unable to find it on any of the outboard forums. Another thing we found is when the motor spin backwards you can take screws out of the starter and spin the bottom cover 180 degrees and reassemble. This will also change the motor rotation.

 

[Captain Colin]

Re: Starter motor spins backwards

I had the same problem. The armature can't be put in backwards, but the field coils which are contained in the barrel or cylindrical part of the starter can be put on upside down effectively reversing the magnetic polarity of the starter and causing the starter to turn backwards. The dead give away in my case that I didn't notice until after reading your posts here, was that the writing and wiring diagram sticker on the side of the starter was upside down! :facepalm:

Thanks for the help. I just wanted to make things a bit clearer for the next guy!

 

[Chris1956]

Re: Starter motor spins backwards

A lot of those starters use permanent magnets instead of field coils. If you install the magnet the wrong way, the starter will spin the other way.l