reversing a starter motor?

[dave21478]

Is it possible to get a starter motor to run in the opposite direction?

The story is....I have a wee Honda single cylinder diesel engine with a dead starter. The motor is made by Mitsuba, but I cant find a direct replacement anywhere for reasonable money. Some random internetting found that it was pretty much the same as the starter for a 1.5 petrol Civic, so I bagged a used one from Ebay. The nose fitting is not the same, but that is easy to swap over, however, it turns in the wrong direction. I tried just reversing the polarity (starter on the workbench) but it still spins the same way.
The motor has 4 carbon brushes in the top.

Is there any reasonable way I can get this to run backwards? Alternatively, is there any other model of Honda that has one turning the opposite way? IE starter mounted on the other side of the flywheel?

Cheers.

[composimmonite]

AFAIK you have to swop around the connections to the brushes. Google showed numerous hits.
If in doubt take to auto electrician who should be able to do the job.

Paul H

[dave21478]

Cheers, just come in from the garage and its quite simple actually.

An old-skool motor with a magnet when connected backwards will turn backwards. Modern motors seemingly don't have magnets, they have a second set of coils which make an electro magnet. Connecting them backwards means that BOTH coils are backwards, cancelling each other out so it turns the same direction as normal. You need to reverse one coil but not the second electromagnet.

In this case, with it all in bits and compared to the melted remains of the old one, its quite simple. The four brushes are mounted on a metal plate, 2 to the rotor and 2 to the stator coils. 2 are grounded to this metal plate (don't know if rotor or stator) and 2 are insulated with wee fibre washers. I just took out the brushes and turned this plate 90 degrees and refitted the brushes and it now works the way I need it to. Happy days!.


Long term, the way the brushes sit and the location of the springs means it will not last as long as a "proper" one before the brushes stop making contact, but I can live with that for now.