Prop suggestion for a Mercruiser 4.3 sterndrive

[mia9516]

Re: Prop suggestion for a Mercruiser 4.3 sterndrive

Were just looking for potential issues...Some things just dont add up giving your gear ratio is part of the process it will help determine many things.....After all your prop is going to be your final gear and they do cost money...

That figure i threw out of 165 hp was just a WAG....But a 165 hp motor should push a boat of that size to at least the mid 40's or low 50's even

I got a good look at the outdrive. The port side label reads "1.64R" and "OB799766". What does this say about the gear ratio? Too low? Too high?

I also got a look at the cap, rotor, and plugs . I may have opened a Pandora's Box. She's been so neglected. I should have suspected it when folks were saying I should be doing 40mph or better. Looks like I've got my work cut out for me before 4th of July weekend. Thanks again for all the help everyone.

 

[180shabah]

Re: Prop suggestion for a Mercruiser 4.3 sterndrive

1.64 is the gear ratio (if it hasn't been regeared), and gives you a slip of 26% at 4400RPM. Now that we know you have some tune up issues to take care of, we can assume that your WOT RPMs will come up significantly. Your prop slip should come down as speed increases also.

Once, you get it runnin' right, make another WOT run and fet us the new numbers.