laccanookie
New member
Hello, My question is does a 1984 Yamaha 70 h.p. lower unit interchange with a 90 h.p. I have heard it does it looks like it will but I understand the gear ratios are different. The 70 h.p. being 2.33:1 and the 90 h.p. 2:1. Is this info correct ? and if so could that difference be made up with a different pitch or smaller prop and not be destructive to the 70 h.p. ? Oh and I'm new here so hello everyone and I look forward to making new friends and learning something here Thanx laccanookie