Prop Selection Help

Here is what I'm working with 15hp Johnson on a 14' jon boat. With 9 1/4x10 prop at WOT its 4750 rpm. Using a 91/4x5 at WOT its doing 6750. Service manual calls for 5500-6500 rpm range. These test are with a loaded boat. Me, son, lot of fishing gear plus newly added front deck. What recommend prop size do you think would put me in the sweet spot I'd say around 6100-6200 Rpm :?:

These are the speeds getting out of prop on the 10 going upstream with load about 11.6 MPH :LOL2:
Here are the speeds getting out of the 5 going upstream with load about 7.4 MPH

I would go with a 9 1/4 x7

FYI . . . page out of my 1987 Nissan NS15B manual . . . run on a 14' Lowe . . . also tracings of the 2 props I use (more pitch doesn't equate to more speed on a 15HP)

[url=https://www.tinboats.net/forum/viewtopic.php?p=353526#p353526 said:

stevesecotec02 » 25 May 2014, 17:25[/url]"]I would go with a 9 1/4 x7

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:lol: That's what I was thinking 9 1/4x7