Prop Information

Kadetsr

Recruit
Joined
Aug 12, 2002
Messages
4
I still need to know recommended prop size for 1990 Johnson 40 HP. Can anyone help?
 

Jack Shellac

Lieutenant Commander
Joined
Aug 7, 2002
Messages
1,661
Re: Prop Information

Suggest you get a Michigan Wheel catalog {may have web page, also]. They have some pretty good guidelines for prop selection. Is also a good prop.
 

MGuckin

Senior Chief Petty Officer
Joined
Jun 10, 2001
Messages
760
Re: Prop Information

Please keep your posts in the same thread. It is very confusing when we have to search for info.<br />I believe you may have 2 problems.<br />Motor is not mounted at the correct height. Do a search on x factor.<br />Prop is keeping rpms down.<br />Adjust x factor to achieve max rpms and handling first. Rpms s/b about 5500 at wot, assuming motor is running at its optimum mechanical capabilities. <br />If not you can try a different prop.<br />I think you will find that you should be running a 15" not a 17" but your max rpm is still way off even with the different prop pitch.<br />If only running 4400 rpm and tach, is in fact accurate, you are lugging this motor bad.
 
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