1953 1/2 ton with a 261 using a rebuilt foot starter on a 12 volt sys. Normally starts fine but today i stopped at the store and when i came out and tried to start it the foot pedal felt funny like it was not up as high as normal. Luckily i had some tools and started checking things out. I finally took the starter off and I could tell was in a bind and when i put it back on it started right up like normal. It's done this before but it's rare. Any ideas what the problem might be