After having the shaft for the starter shear in half and being towed in, I bought a new starter from ARCO. When I pulled off the old starter there was a larger, like 1/4 inch thick washer that came off of one of the three mounting bolts. I didn't notice it at first but now wonder - 1. why only one such washer type 'something', 2. what's its purpose and does it matter what bolt is actually goes to, 3. should all three bolts have one of these? Any info would be appreciated. Easy fix. The dealers wanted over 400 for a new starter and the ARCO recommended by a Mercury dealer was 208. Any ideas.