FASTERDAMITT

First are you blowing out the prop or is the rpm to low to get on plane? From your top speed it sounds like the engine is low on power to me. Something wrong! Not enough torque. Low compression most likely. Do a compression check to see where your at. Are you using gps for speed calculation? Do you know your gear ratio? If 1.5 you shoud be at 80mph with a 26 at 11% slip, 5500rpm. Make sure your outrdive trims in all the way. I wonder what the tilt in angle is on the unit. Maybe need a spacer to bring the outdrive in more.

CA_Southpaw

Parden my ignorance on the subject matter...but, my rpm's when getting on plane are around 2400-2900. Regarding my power, I know something isnt right somewhere. But, I doubt its the powerplant. Thing has 80hrs at most on a rebuild. 10:1 compression. I did a compression check before I purchased it and it was well above standard. Not using GPS. Gear ratio is 1:46. Regarding your assessment of the top spedd, I believe that is where I should be all day as well, from reading other topics on AO's that have far less HP than my motor. My drive does trim in all the way. It does have an extension box on it. The tilt angle, when its trailered, it actually tilts 'in' towards the boat. In other words, when looking at it eye level, from the side, the drive isnt exactly verticle to the ground, it actually is pointing a hair towrds the hull. Here's one more piece of info., the boat has a transmission in it. Which, I have heard robs roughly 10% power??? Not sure of it though. Thanks for everyone's time.

CA_Southpaw

Not sure if a visual will help. But, here's a couple of pics of my outdrive.

Xray50

Southpaw. See your PM's..

FASTERDAMITT

My quikest answer is you cam is a little big for your set up. Lack of low end torque. Your speedo tube is getting a mixture of air and water causing it to read low.

FASTERDAMITT

I had to run a longer speedo tube when I had mine. It was 5"s below the bottom. Otherwise it was erratic.

CA_Southpaw

Applying some common sense here leads me to believe this is the direction to start looking in. Because, when I had my 26P on, 6 adults, we all had to stand to plane. Even then, there were times where I had to give up, and try again, because it sounded like my engine was going to stall from the struggle. Last weekend when I had that lab finished 28P, 4 adults, we had to stand up. However, even then it (the motor) was still struggling. Struggling by bogging down as if it was going to stall.

quest

With a 26 P bravo 4 blade and 1.46 gears this boat will run 79 MPH at 5500RPM and require 480 prop HP with 6 people on board. Your 68 mph is incorrect. Borrow a hand held GPS and check the speed.

Motor should not lug when getting on plane. Sounds to me that the bottom end hp may be too low for 4 to 6 people on board. This could be caused by too large a cam.
How does it plane with only you on board and what is the speed and RPM.

FASTERDAMITT

I think that's what I said.

Xray50

The hulls on AO's are not condusive to quick planeing. I have a 540 BBC. When I first bought the boat it had M1 procharger on it. At 2500 rpm's it would leap out of the water and as soon as the blower kicked in. That was with a 30pitch Bravo 1. Remove blower and fuel injection. Now running a 850 holley. I use the 30P for top end and 2 people in the boat. Takes me 8-10 seconds to get on plane. A 26P takes me about 5 seconds to get on plane. 80 gals of fuel and 4 people. Motor does not have low end torque. Also the boat like stock Bravo 1's. 15 1/4 diameter. Anything less and cavitation goes wild. I had the cupping removed and blades thinned out and it cavitates too bad to even use.