75hp johnson prop size/pitch?

[75-JOHNSON]

what is a good size and pitch to run on a 1976 75hp johnson? right now it has a 13.5 inch, 17 pitch and it has almost no bottom end, and takes forever to come out of the hole even with only one person in it.

 

[1kruzer1]

Re: 75hp johnson prop size/pitch?

We can't tell you what pitch prop to run as it entirely depends on the boat you are pushing. What you need to do is select a prop that gives you close to 6000 RPM as measured with an accurate tachometer for that particular motor at wide open throttle. Lots of things can affect acceleration performance. Improper trim, low compression, dirty carbs, sticky timing plate, malfunctioning ignition, link and synch, and the list goes on.

Once you are confident the engine itself is properly tuned and there's no mechanical malfunction, then prop for 5800 to 6000 RPM as mentioned above.
Good luck!

 

[steelespike]

Re: 75hp johnson prop size/pitch?

If you read the stickies at the top of the page and the helps at the prop store page
get back yto us with the details of your setup we can help with a prop selection if that is the required solution.

 

[1kruzer1]

Re: 75hp johnson prop size/pitch?

We can't tell you what pitch prop to run as it entirely depends on the boat you are pushing. What you need to do is select a prop that gives you close to 6000 RPM as measured with an accurate tachometer for that particular motor at wide open throttle. Lots of things can affect acceleration performance. Improper trim, low compression, dirty carbs, sticky timing plate, malfunctioning ignition, link and synch, and the list goes on.

Once you are confident the engine itself is properly tuned and there's no mechanical malfunction, then prop for 5800 to 6000 RPM as mentioned above.
Good luck!

I should add that when I said "for that particulat motor" I was referring to RPM near 6000, NOT any particular tachometer. Any accurate tachometer set up to read for the correct pulse rate will do.