Do starters slowly die, or just die at once?

[Weblamer]

Odd problem with my scooter starter.

The starter had been feeling 'slow'. Cranks real slow but eventually fires up the scoot. Eventually it stopped running. I figured it was a dead battery, so I bought a new one, and gave it a good charge before I put it in.

That fired it up once or twice, but ended up feeling 'slow' again until eventually I just got the relay clicking.

Busted out the meter, the battery was fine and the starter relay is good.

So I think its a bad starter, however I always thought they just died out at once, not slowly grind down?

Could there be a short somewhere drawing power from the starter?

I would like suggestions before I tear it down and order a new starter.