New to the Inboard outboard world.....

[72seastar]

what is the purpose of the trim feature that moves the outdrive up and down other than lifting it out when on trailer to keep from dragging the ground? i know you can adjust it while in the water and there is a gauge for it (mine is broken) i just stick it all the way in the water and go but i understand that can affect how fast you can go???? how and why and what am i supposed to be doing?

 

[craze1cars]

Re: New to the Inboard outboard world.....

Generically speaking, all the way down is fine for accelleration...helps the boat plane out faster.

But once the boat is up on plane you want to start trimming up. It will make the boat go faster, will save fuel, will handle and steer better, etc. Rarely does a boat handle very well with trim all the way down all the time.

Every boat is different. Play with yours. You don't need your gauge fixed to experiment. Next time you're boating leave the trim all the way down and set your speed at approximately 25 or 30 mph and let it sit there. Now start trimming up. You'll probably see your speed increase. Sometimes as much as 5 or even 10 mph plus....without ever touching the throttle. The faster you are going, the more trim impacts your speed. Eventually the prop will start blowing out of the water a little bit and the RPMS will go up as the boat slows down. Now you've gone a bit too far...so just inch it back down a bit and the prop will re-bite, RPMS will drop a bit, and speed will go up a bit. Usually right at this point is your ideal trim for that particular throttle position.

Basically the ideal trim setting for any boat at any speed is the max speed you can attain at any given throttle position. Most knowledgeable boaters are on that trim button CONSTANTLY. Almost every change in speed, change in water condition, turn, accelleration, decelleration....almost every circumstance takes a different trim setting, if you are truly trying to have the best handling, performance, and efficiency.

 

[72seastar]

Re: New to the Inboard outboard world.....

the thing ive noticed leaving it all the way down and advancing the throttle is that it speeds up to a certain point as im giving it more throttle and then it just stops going faster the throttle will keep going and i can tell a difference in the engine but no more speed.... im gonna have to try and play with it more next time im out ive only had it out 2 times.... i want to order all new gauges.... the only 2 not working are speedo and trim but the others all have cracked faces an the like im looking at some Faria Chesapeake White Ss Instruments gauges

 

[Bamaman1]

Re: New to the Inboard outboard world.....

After planing the boat out, trim the outdrive up until the boat starts rocking slightly. Then, tap the down button a touch or two--until the boat stops porpoising. That's usually the best "trim" to run your boat. Most cruising is done at constant speed/rpm's in the real world.

After you get your boat on the trailer, try to keep your outdrive down as much as possible--while in storage. That takes the stress off the rubber bellows over the drive shaft, exhaust and the F/N/R cable bellows.

 

[weareallnuts]

Re: New to the Inboard outboard world.....

Watch your tach compared to the speedo. Changes in trim will affect the ride and speed. I also like the hydrofoil tail; on my old Cobia, it made all the difference in the world in the ride, keeping the nose down when starting, getting the boat up on plane quicker at slower speed/rpm.

Take a look at this thread, also:
http://forums.iboats.com/showthread.php?t=488405&p=3371445#post3371445

Peter in SC

 

[weareallnuts]

Re: New to the Inboard outboard world.....

That's because the boat is not up on top of the water as much as it should be -- planing hulls, even deep v's, are designed to ride up on top of the water. When your outdrive is trimmed all the way in, it will get you up on plane faster, but then too much of the hull is making contact with the water, reducing speed and efficiency. That's why I like the hyrdofoil tale on an I/O. It increases lift at the rear of the boat, getting you up on plane faster at lower rpm with the engine trimmed up more than before. I asked a mercruiser rep once why they don't just make the cavitation plates bigger, he gave two answers -- the "factory" answer was something about making them generic for all boaters, and his answer was, because they don't want to admit the problem!

Peter in SC