Newcomer - Please help me understand trim

[marcoalza]

Hi, My first post to iBoats which I have been reading for some time now since purchasing my Q4 SF.
Can the experienced out there please give me some advice.
I have learnt a great deal by reading previous posts but need help on trim.

Can you explain in laymans terms how to trim and what to watch for?
What is the goal of trimming?
The person who sold me the boat said to keep it down at all times?
What to do in different conditions?

The only thing I know at the moment is to raise it when close to the beach!

I will appreciate your help.

Thanks......

 

[Boatist]

Re: Newcomer - Please help me understand trim

Welcome to the Board

The goal in trimming is to get the boat to ride in the attitude that you want.
The goal may be a better smother ride or more speed or better fuel mileage.

To begin with before taking off and bringing the boat up on plane most people will trim the motor down or in. This causes the motor when under power to raise the stern of the boat some making it faster and easier to get up on plane.

Once the boat gets up on plane and the bow come down on the water you can now trim out or up to raise the bow for the ride you want.
Raising the bow should also give you more speed for the same throttle setting and also better fuel mileage especially if your not at full throttle.

The trade off of course is the bow is now riding higher and the boat is riding on a flatter part of the hull so if the water is choppy the ride will be much rougher. Also on many boat depending on how it loaded the bow will start to bounce up and down. If it does then you should trim back down or in slowly until it just stops.

In really rough water trimming down or under will allow you to slow down but stay on plane at a lower speed for a safer ride.

You say raise it when close to the beach. That is a good idea at idle speed and when it gets to a certain point it will raise faster. This faster part is called tilt. Motor should only be tilted up a very small amount and only at idle speed for a short time.

 

[Philster]

Re: Newcomer - Please help me understand trim

Your boat is designed to maximize performance/speed with the trim up.

Trimming up will lift more of the boat out of the water, reducing drag.

It is not advised to run hard and to make full throttle runs with the trim down. Trim down you might hit 35. Trim up and you might hit 50. Trimmed down the engine will lug hard if you go for a top speed run and this is bad.

It makes that much of a difference.

Get on plane trimmed all the way down.

 

[marcoalza]

Re: Newcomer - Please help me understand trim

.....a couple of really helpful posts. Thanks for you time and effort.

 

[blifsey]

Re: Newcomer - Please help me understand trim

Two things to add..

Boatist mentioned the boat may porpoise (bow bouncing up & down) if you get trim to high. Another thing trimming too high may do is cause prop cavitation. This is when the prop get to close to surface and begins to slip similar to a car losing traction and spinning its tires. If this happens you will notice your RPMs will increase suddenly. Like with the porpoising, just trim down a little until it stops. On our first bass boat, it would porpoise if I trimmed too high. On our Glastron bowrider, it would cavitate instead.

The second thing is when going into a hard turn, you may need to trim down just a little because the boat lean will cause the prop to get close to surface and cavitation is possible.

 

[ziggy]

Re: Newcomer - Please help me understand trim

google is your friend... http://www.google.com/search?q=how+...s=org.mozilla:en-US:official&client=firefox-a

check out the top three at least.
the bennet trim simulator is kinda fun too.

 

[njmedic3306]

Re: Newcomer - Please help me understand trim

With smaller boats you may nead to use the trim more often based on passenger load. If you have people sitting in the bow you may need to adjust the trim to keep the boat from dipping too low.

 

[a70eliminator]

Re: Newcomer - Please help me understand trim

My wife likes it when I trim way out and ride with the bow way up she get a big kick out of looking down the stern wake, I then have to kneel on my seat back to see over the bow, just something else to play with, my other boat doesn't have hydraulic trim, I have to set the tilt pin and leave it.

 

[Alpheus]

Re: Newcomer - Please help me understand trim

Newcomer - Please help me understand trim

Thats something my father explained to me when I first started Jr. high school...

 

[marcoalza]

Re: Newcomer - Please help me understand trim

Thanks for all your responses.

I am really looking forward to getting out soon and putting all the advice to good practice.

Great Forum, thanks again.