TOPIC: Bronze Bearings

Can anyone tell me if or when OMC stopped using bronze rod bearings in the smaller motors?

How small? The 4hp retained babbit bearings right up into the mid-1970s, on both ends of the con rods and at the center and lower mains. The 6hp had them on the wrist pin ends up to about 1976 or 77, along with center and lower mains.

Most of the 9.5 & larger 2-cylinder motors had ball & roller bearings by the mid 1960s on all but maybe the center main, and 3, 4 & 6 cylinder motors were fully steel bearings.

I was most concerned with the 5 1/2, 6, and 7 1/2, and 10.

The 5-1/2 picked up needles around 1963 or so, on the crank end of the rods only.

The 7-1/2 of the 1950s never got steel bearings. The 1980s era 7-1/2 was fully jeweled.

The 10 went to steel bearings on all but the center main by about 1961.

I don't have my parts books in front of me, but that's pretty close...

Thanks Scott.