Out of water RPMs- 3750
Just me and some gear -3650
Me and a buddy + dog and gear - 3550
9 x 7 Beavertail Prop
16' Lowe, 74" across the top, (I don't know what that means as far as size goes and I never weighed it) Pictures attached.
I haven't GPS'd speed, does this drop in RPM's seem correct and is there more in the tank if I set it higher? I'd like to get some run time first!

out of water rpm's seem low to me. maybe 4200 or so. at least on the old carbed 27 knolers it was that way. I put thousands of hours on several of them. great motors.

I have a 26.5 Kohler backwater longtail. I goosed the RPMs by buying a longer screw that added more tension to the governor spring. With a hunt load by myself I will run around 4070 to 4120 RPMs. The coils have a preset maximum rpm so there are no worries there by changing the governor spring tension. By far though, I am not the expert. Good luck and I hope this helps..

Did you get any extra vibration with going that high? I'll try it once I get some hours on this motor.

Have been running it that way for about 4 years now with no problems.

When you finally get it all worked out, please post back here or PM me with the speeds you are getting. I get about 20 miles per hour with myself and a hunt load. Looks like you have a go-devil. My backwater is mounted on a Gator Trax 1644.

Yes I will do that
Thanks for the advise