Gear ratio

[RICKRICK1]

What is the gear ratio for aa 1967 65hp inline 4 mercury?

 

[Spidybot]

Re: Gear ratio

That's tough. I can find it's weight (100 kgs) and that it's 65hp at 5000 rpm. Nothing about gear ratio.

 

[RICKRICK1]

Re: Gear ratio

Thanks for repling, I am trying to validate the mph Im reading on my speedo, all formulas I have found use the lower end gear ratio and it is not in my manual.

 

[RICKRICK1]

Re: Gear ratio

UU I checked again and found another post which came close ratio is either 1.64 or 2.3 as near as i can get. On your post "wisdom" of prop's everything I enter says I should be running a 17 pitch prop and getting 32 mph. All I get is about 28 mph wot at 5100-5200 rpm with a 15 pitch prop. have tried a 17 and hole shoot is really slow, but can get on plane. with the 15 pitch have good hole shoot and plane not much different on wot mph. 1984 Tidecraft (BB), 1967 65hp merc. comp all cyclinder is 130 to 135. Carb are good and merc running good. If you or anyone else have an idea to mph up to average please reply. Again THANKs UU.