89 force 50 planeing and tach issue

[ozzy15]

Hello All.
Any help will be appreciated.
I have a 15' bay liner with a force 50.
I got the boat running. I took it in for a carb rebuild and it runs great!
I have 150 psi in both cyl. Fresh gas mixed 50:1.
I can not get it to come up out of the water with more then 2 people, 400 lbs. She just drags thru the water 3500 rpm. when I do get her on top of the water she is running about 6200 rpms.
I am running a 11.5 pitch and bought a used 10. The ten pulls a little better but not much. The spedo reads about 20 mph planeing....
from what I read I need a smaller pitch to get out of the water and a higher pitch to slow down the rpm.
I did install a hydro fin on the motor to help plane.
Any ideas?

 

[jerryjerry05]

Re: 89 force 50 planeing and tach issue

Most boats are designed to operate without an extra fin.They only confuse the issue.Put it on after you get it running good(if you must).
The prop you should have is a 13 maybe a 15 those low pitch props are for pontoon boats(my opinion). Jerry

 

[djsforce]

Re: 89 force 50 planeing and tach issue

I have the same issues with my 50 hp. It may even be the same Bayliner 1401? The first year I had it was the worst, even took it to a mechanic who said it met the specs of a brand new motor. The next year I changed the lower unit gear oil and it improved a great deal. My manual for a 1994 Force says full throttle RPM should be 5000-5500. My prop has a 13 1/2 stamped on it and the boat runs around 28 mph at full throttle with two people. This year I've installed a Tiny Tach and I'll see what RPM I'm running. Also if your Bayliner has the built in tank, keeping it lower on fuel will help in planeing.