trimming your outdrive help.

Joined
May 6, 2012
Messages
8
how do you trim your outdrive properly. I have always put the oudrive in the full down posistion and left it there. i am looking to get on plane a lot faster and keep plane at a lower speed so i can tow a rider on a tube without screaming around the lake and wasting fuel. when you get the trim set just right do you move it when you go to take off again. i was told by a family meamber to get on plane and bring the out drive up a little at a time untill your rpms start to drop. i do not know if this is true on not.
 

dsiekman

Senior Chief Petty Officer
Joined
Jul 7, 2010
Messages
798
Re: trimming your outdrive help.

That's going to depend a little on your boat. I start trimmed full down/in and bump it up once on plane. Your RPMS should go up as you raise the drives. Depending on what I'm trying to deal with - flat calm, wakes, chop, etc., I usually trim until she starts to porpoise and then back off until she stops. For me, trim adjustment is frequent while under way unless I'm running in dead calm water which almost never occurs.
 
Joined
May 6, 2012
Messages
8
Re: trimming your outdrive help.

the lake i go to has slight to moderate wake/ chop . i also just bought a doel fin to help.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Re: trimming your outdrive help.

the lake i go to has slight to moderate wake/ chop . i also just bought a doel fin to help.

You're not sure how to trim properly but you buy a whale tail to help???????? The only way to learn how to trim properly is to PAY ATTENTION to what the boat is doing. You start trimmed down. Failure to do that causes the bow to rise very high during hole shot. As the boat comes on plane "bump" the trim in small increments. The seat of your pants will tell you when trim is proper. Trim too far up and you may experience porpoising or prop blow-out. Trimming for any other speed or condition requires experimentation. Every boat and every load is different.
 

dsiekman

Senior Chief Petty Officer
Joined
Jul 7, 2010
Messages
798
Re: trimming your outdrive help.

the lake i go to has slight to moderate wake/ chop . i also just bought a doel fin to help.

Be careful with that doel fin. A buddy of mine added one to his older outboard. It worked "so well" that it allowed him to over rev the engine at which point the piston exited through the side of the cylinder. Whoops. :facepalm:
 

gozierdt

Petty Officer 1st Class
Joined
Jun 13, 2010
Messages
364
Re: trimming your outdrive help.

Asking for advice without giving us some details on your boat is usually an exercise in futility. How can
we give good advice unless we know something about boat length/type/weight, or engine size? Also,
you'll find the various "fins" for the outdrives are not thought well of by a majority of posters (I'm judging
by how many + and - replies I see to that topic), for anything but small fishing boats.

In my opinion, if your boat is a typical 18-22 foot deep-V outdrive, SmartTabs would be a much better
solution to your problem. You seem to not want to mess with the trim. Smarttabs would allow you to
trim your drive out once (or at least not every time you go in gear), would still keep the bow down as
you accelerate, and give added benefits, like less bow wandering at low speeds. They're basically "set
and forget".
 

chizwizdiz

Seaman Apprentice
Joined
Mar 14, 2011
Messages
39
Re: trimming your outdrive help.

That's going to depend a little on your boat. I start trimmed full down/in and bump it up once on plane. Your RPMS should go up as you raise the drives. Depending on what I'm trying to deal with - flat calm, wakes, chop, etc., I usually trim until she starts to porpoise and then back off until she stops. For me, trim adjustment is frequent while under way unless I'm running in dead calm water which almost never occurs.

Same here. I start with the drives, and tabs down. Then, as the boat comes on plane, I adjust the drive trim up until the ride get's too uncomfortable, then back it down a little, then level out the boat with the tabs. As someone else said, you have to be mindful of RPM's, because they can sky rocket very quickly.

Adjusting the drive trim in your case would be different then mine. I usually hop on plane and cruise for about two miles at a fairly constant speed, you pulling tuber's around would be constantly changing the drive trim.
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,544
Re: trimming your outdrive help.

You need things to lift the stern if you want to reduce your planing speed. I know that there are bow lifting props that bass boats use and I currently have on my boat. I also understand that there are stern lifting props that would help a stern heavy boat lift it's stern. I'd say that and adjustable trim tabs would help you along with doing what you already do and that is tucking the trim all the way in when pulling the tubes. I never ran a whale tale. Didn't want to drill holes in my AV plate.

HTH,
Mark
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
Re: trimming your outdrive help.

what kind of boat?
what kind of drive?
what motor?

learn to use the trim properly and return the tail.

here is the method I used to trim the drives on my 3.0 liter boat when pulling skiers/tubes with only 2 people in the boat - drive full down, then WOT for the hole shot, as the bow is coming down, and the speed increasing, I am trimming the drive up and backing off on the throttle. I am also watching the GPS speed for tubing. generally the drive was about 1/4 way up on the gauge. Now here is the caveat. with 4 people in the boat, the motor needed a bit of help. I usually had everyone move to the front for the holeshot.

on my 5.0 liter boat, I found that I had plenty of power for one or two tubes and could get lazy. once trimmed for optimal planing (again, about 1/4 up on the gauge), I would just leave it and use the throttle. now, for pulling two skiers, I would have to trim all the way down until the boat started to plane. trim tabs would be down just a bit, however not too much to cause too much drag.

leaving your drive all the way down is snow plowing your bow.
 
Joined
May 6, 2012
Messages
8
Re: trimming your outdrive help.

the boat is a 1969 seaflite with a mercruiser outdrive with a 3.0 inline 4 cyl i have about 2 to 3 adults and 2 kids in my boat at a time towing a one person tube with the two person tube cut the adults down to 2. i also keep an eye on the rpm so that wouldn't be a issue. far as the trim gauge go i don't have one on my boat.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,296
Re: trimming your outdrive help.

if you dont have a trim gauge, then simply have it all the way down for the hole shot, and as the boat comes on plane, start raising the drive just a bit and back off on the throttle. if you raise it too high, the boat will start to porpoise
 
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