Proper Trim

[Down The Hatch]

I'm a little confused and maybe I could get some help.
Are you supposed to run an outboard at full throttle with the trip set all the way down?
I was told this by the mechanic at the marina I go to and have read articles in various magazines that you can trim it up. Looking for maximum performance from the engine. Any help would be appreciated.
Thanks

[Gerry Zagorski]

It depends, each boat is a little different and conditions vary as well...

In general, if you're running in flat conditions you want to trim it up as high as possible without the prop cavicating... This will left the bow and reduce the amount of wetted surface of the hull and the less hull you have in the water, the less drag and more efficiency you'll have...

Having said that, raising the trim up in less then ideal condition will make the bow come up, could cause excess porpoising and if your going fact you could launch the boat out of the water off waves... In this case you'd need to trim it down to keep more of the bow in the water..

The other thing a lot of people do to get up on plane faster is trim the engine all the way down when taking off and once up on plane, trim it up...

Best thing for you to do is play around and see how far you can trim it up and still get a comfortable ride in the conditions you are in at the time.

[Down The Hatch]

Ok will work on that. Thanks.
I had a strange noise last year coming from the engine and the mechanic thought I had the boat too high. Lowering it made the noise go away

[NJSquatch]

check out youtube vids

https://www.google.com/search?q=prop...t+trim+youtube

[Capt. Debbie]

You ideally want the prop thrust parallel to surface for maximun cruise efficiency. Not angled up or down at the slightest

HOWEVER getting on plane it should be down. Then back off trimming up when on plane. Bow plowing (trimmed too far down) is inefficient and slows the boat and makes it harder to steer since the buried keel is steering too with each wave it hits.

Get on plane. Set throttle(s) and study your GPS. See what trim does WITHOUT touching throttles. Gaining or lossing mph over the bottom with each touch of button. It will vary as much as 2 knots. REMEMBER you are getting 2 more knots for the same amount of fuel. People misunderstand that throttle position controls fuel fuel flow NOT RPMS

Ideal max efficiency trim is on plane with prop thrust parallel to water surface. No pushing up or down- just straight ahead thrust. No wasted power. If you look back with OB's the top of the O/.B is also flat without incline decline parallel to the water surface.

Additionally sparingly use trim tabs. These run on DRAG. Engine trim is the most efficient.

[Down The Hatch]

Thanks once again for the help