Hello all,

Have a grounded out starter due to plastic insulator on positive end. Tore down and cleaned up commutator as well as brushes and replaced insulation. Brushes and commutator had minimal oxidation but quickly cleaned up.

Now will not turn when hooked up to battery.

Original part was 067050800. Replacement starters have part numbers 270400111A,27040111A,128000-6050 and appear to be an identical fit.

Rotation direction of newer starters has been alluded to, however no facts.

Please let me know any ideas or suggestions, as well as if the above later part numbers will work.

Thanks,

Chris

I have no ideas why your original starter no longer works. Assembly?
The part no for the 907ie is 27040011A and is the same for the 900SS through to the injection models and also the ST2. The crankcases are basically the same throughout. This was superceeded by part no. 27040051A starting with the 749/999 series but is interchangeable with the earlier part no. This part no is continued through to the 848/1098 but the reduction gearing of the starter drive pinions was lowered. My MTS1200 has a different part no 27040101A and the starter motor pinion is no longer shown as a separate part, but the crankcases are the same as the 1098 so the earlier starter must fit too.
I conclude that all the starters are interchangeable but you may need to swap the pinion if using a later one.

are you sure the relais is working properly?

you can bypass the relais by "jumping" the starter directly from the battery, this way you can narrow the problem.

The other thing is that you disassembled the motor, can you fit the brush plate "the other way around or at 90 degrees? what i mean is that sometimes the position of the brush plate can effect the electric motor operations.... not sure if it can be applicable to a Paso starter, but I am quite sure that can occur on DC motors.... it is just a thought!!

Found the problem. The outside plastic insulator on the positive terminal had crumbled and shorted to ground. Wonder if I can get a warranty from Ducati after 28 years?

Put on rubber and phenolic washers and sealed up with RTV. Starter works now and off to other issues.

Thank you for your response!

up grading/sizing the standard cables associated with the starter and earth can improve the starter performance significantly , there are even kits available ( FAQ's )
Hamish