I needed to replace my crankcase pulley on my M25 21 horse power Universal Diesel motor. When the tension from the belt was off, there was close to 1/4 inch of slop in both directions. I suspect that the larger alternator (120 amp) was creating more tension over the years then it was originally designed for and the key became worn. I ordered a used pulley from TOAD Marine which solved the slop problem but I realized that the pulley was 1" diameter larger than the original pulley. Will this larger diameter effect other parts of the engine? According to a local diesel mechanic it will not. Any other thoughts on this?
