Gear Ratio ? for Bruce

[JohnCranston]

Hi Bruce,

If you could help me with these questions, I would very much appreciate it. The three engines I am considering for my very light Bahia Mar are 240 & 315 Yanmars and Model 256 Steyr. What brand of transmission and what gear ratio should I go with on each motor?

I am getting ready to pull the trigger on a new pair and I want to have all my ducks in a row.

Thanks again for your help John

[Capt. Mike Holmes]

John, I think most of the high rpm diesels like the ones you listed use 2:1 gears in a 31 Bert application. I've mentioned I'm happy with the 1.91:1 Twin Disc 5011A gears I have now, although I had troubles with the 1.45:1 ratio in the same gear. I'm sure either a ZF or TD will work for you, the 5011A TD is probably smaller and lighter.

[Bruce]

John,
2:1 ZF 63 on all.

[JohnCranston]

Thank guys that is what I needed to know. I will let you know what I do.

John