Need some trim advice.

[lee74carlson]

New boat owner have learned a lot, mostly the hard way. I have a 96 Bayliner with a 5.7L 350 Mercruiser, 210 HP. We mostly bought it to ski in. It has an Alfa One out unit. I am having a hard time getting skiers out of the water, especially single skiers. I set the trim all the way down to get the bow to plain out faster is this correct? I have never had to work so hard before getting out of the water. I only weight 190 pounds and am a good skier. A 350 should be plenty to pull me, right?

 

[DJ]

Re: Need some trim advice.

lee,<br /><br />You would think a 350 would be plenty. However, not in a 25' boat. You didn't mention what size boat.<br /><br />Anyway, what is your top achievable RPM with a light load? If you are not reaching your desired RPM range, you may be overpropped.

 

[lee74carlson]

Re: Need some trim advice.

My boat lenght is 20', I am getting 4200 RPM at WOT and the book says 4200-4600, is that about right?

 

[DJ]

Re: Need some trim advice.

lee,<br /><br />I believe you are on the lower end of your operating range.<br /><br />I do not know what pitch prop you are running. However, dropping a couple of inches of pitch will help your holeshot a great deal.<br /><br />As an example. If you are runnning a 21" pitch prop and turning 4200, a 19" pitch prop will turn 4600. A rule of thumb is one inch in pitch equals 200 rpm.<br /><br />I think you are overpropped for what you are trying to do.<br /><br />A 350 2 barrel is not considered a great deal of hp. for a 20' boat.<br /><br />You are doing everything right, you're just trying to take off in second gear.

 

[lee74carlson]

Re: Need some trim advice.

Hey thanks for the info I will have to check to see what size prop I have. Where would be the place to look for it?<br />Lee

 

[Boatist]

Re: Need some trim advice.

Lee<br />Most of the time in the hub area. May need to remove the cottor pin and prop nut and washer.<br />Many times will have Part Number only but some have size stamped in. With part number can find size and pitch.

 

[lee74carlson]

Re: Need some trim advice.

Hey Sactown,<br /> Thanks for the info I will be looking into that and possibly a new prop. Thanks to all for the info. This site is the greatest.

 

[llerrad]

Re: Need some trim advice.

I do the same with my rig same size and power, I put whale tale on the lower unit and it planes much faster.

 

[lee74carlson]

Re: Need some trim advice.

Llerrad,<br />I have a stupid question, what is a whales tail?<br />Lee