Need more RPM'S but not finding a smaller pitch prop

I have a 1972 Steury Craft model v415 listed at 810lbs, 14'6" semi v hull rated for 60hp engine.

The engine is a 1968 65hp v-4 Johnson. with a current 10X9 1/4 prop.

The max RPM at WOT listed for this engine is 5200, at WOT I'm around 43-4400 RPM's.

I played with the trim and tilt in all the positions this engine offers and found the best spot but still getting the low RPM's

I'm ok with me and another person on board getting on plane but she won't get on plane with a skier behind and with a full load 4 average size people its slooooow going getting on plane. Even when I'm on plane I never get that full throttle sound the RPM's just aren't there. I can't find a lower pitch prop for this engine anywhere. Anyone with any ideas on a pitch and diameter I should be running on this set up??? Iboats doesn't even list a pin drive propeller for my enigne that is 10X 9 1/4 is this even a size I should have on my engine?? Any insight would be VERY helpful. My boats no fun right now

Re: Need more RPM'S but not finding a smaller pitch prop

You will need to post gps speed and accurate tach readings.

I have a 14'6 semi vee with a 25hp mariner, and with me gear and another guy i am close to your wieght, i get on plane in around5-7 secounds with a 13pitch prop, our dia. may be different but just as a compairison So i think you migt have somthing wrong in your set up.

Re: Need more RPM'S but not finding a smaller pitch prop

I'm sorry I forgot the speed I'm doing 29-30 MPH according to my GPS once on plane but its taking about 12+ secs with me and one other person to get on plane. My tach. is reading 43-4400 rpms at wot and that's the most accurate I can get with the RPM's I don't know how much more accurate I can get with them???

Re: Need more RPM'S but not finding a smaller pitch prop

I'm thinking something is very wrong here.

First, I'd take the boat (w/ trailer) to be weighed. See how far off the weight the boat is. I'm wondering if it could be water logged (heavy).

Next I'd take the motor and while it may seem to be running well, it may have carb issues or whatever that's loosing power.

I'm thinking that setup should be litterally jumping out of the water when the throttle is punched.
Having a hard time believing a over powered, under propped boat that acts the way you're describing doesn't have other issues.
Sounds like you're leaving the trailer attatched to the boat when using. (somethin wrong)

Re: Need more RPM'S but not finding a smaller pitch prop

Son of a Bit** your supposed to disconnect those things??? I always just left the trailer on for ease of loading and unloading... I really think she is running well however I can check into a few things. I have never dealt with a pin drive prop before and wanted to make sure there is nothing I'm missing. Why does Iboats not even list that size for my engine?? is a 10x 9 1/4 a standard size?

Re: Need more RPM'S but not finding a smaller pitch prop

I know it sound crazy but iboats does not have everything, they have most but not all.

Anyway i think maybe your tach is off. With out seeing your tach, it is only guesses from us. I have a tach in my one boat that has different setting for 4,6,8 cylinders maybe if yours has settings it could be on the wrong one. If you can pick up a tiny tach, mine have been pretty good for me and seem to be accurate enough.

What is the gear ratio of your motor? What props does a prop wizard recommend?

Re: Need more RPM'S but not finding a smaller pitch prop

My info says only a 60 hp in 65.
Came with a 9 1/4 X 10 with a number of other options with a 10 X 9 1/4 being the only smaller pitch.That motor on that boat should be pretty peppy.Being the max hp.
Is the motor in excellent tune? do the throttle plates open all the way?Is the prop in excellent shape?Is the bottom clean,no rough paint?Is the weight balanced for and aft?If there are a couple of tanks and a battery in the stern it would surely slow the hole shot.

Re: Need more RPM'S but not finding a smaller pitch prop

I did a compression test tonight just to see and one of my cylinders is sitting at just below 60psi the rest are in the mid 90's. So even tho I thought it was running well I guess it isn't. Well it sounds like ring time for this engine. Thanks for all the info on the props and the suggestions