I bought a 27 horse kawasaki mudbuddy a few months ago and finally got it on a boat its a 16 foot fisher flat bottom the motor will turn right around 4000 rpm's out of the water and the governor still isnt fully open, well with just me gas tank and battery it turned 3200 rpms in the water and it was runnin maybe 12 mph and the prop is a 9x7 thats pretty worn out, and I noticed at wide open throttle in the water the governor is opened wide open so it couldnt be that the governor isnt adjusted right. Well my 200 pound brother got in the boat and about the same speed and same exact rpm's. Shouldnt my rpm's be up and my speed with just me in the boat? I put 2 new spark plugs and it didnt help any, the tank and fuel line are also brand new and yes the tank is vented. Whats my problem? I need help its a week today until duck season and I need it fixed any suggestions? Here is a couple pictures of it.

Whats up with the tiller handle?

Thats the hands free option.

it was on a small pontoon they used for bowfishing its not like that anymore i cut it back to like it came you had to have it on the pontoon to stand completely up.

your Rpms sound right .......... have your prop cupped ...but not too much and see if you pick up any speed