Motor trim vs. trim tabs

[stinson]

Hi guys,

My R23 is my first boat with trim tabs as I have always trimmed the boat via the motor trim angle. So what's the general procedure when setting the boat trim angle? Do I use the trim tabs to level the boat and pull in the motor trim to bring the bow down or do I leave the motor trim centered and use the tabs to bring the bow down?

Any help will be appreciated.

jim

 

[BB marine]

Jim,
Any boat with a sterndrive or outboard. I have always advised when in water deep enough for the draft trim the motor in the full down trim angle, Have the Tabs in the full up position while you are cruising at hull speed or slightly above. When you see the boat starting to dig a hole off the stern and the bow wake is gone start to activate the hull trim tabs to help gain some bow wake and keep the bow down. As you accelerate more bring the tabs down more. I will bring them down all the way and then adjust the tabs to level side to side. Once the boat is on plane adjust the tabs for a comfortable boat attitude and level side to side then start bringing the motor trim up to add some bow lift to reduce wetted surface and increase fuel economy and also ride. Depending on water conditions. The amount of motor trim angle will change. The higher the motor angle the lighter the bow is and the more hull pounding you will experience if the water is disturbed. If water conditions are favorable and you want optimal high speed performance slowly increase motor trim angle up and at the same time reduce trim tab angle by retracting the planes adjust both until you feel the boat getting up on the pad.

Every boat handles a little differently even if it is the same hull and motor. Weight distribution, equipment on board and passengers will change how you adjust motor angle and trim planes. Weather and water conditions will also come into play has to the best configuration of plane angle and motor angle.

Go play with it. The more experience you get you will find the best combination for the way your boat is equipped and the amount of passengers you carry onboard.

 

[stinson]

Thanks for the great explanation Brian.

Will practice hopefully today!!

jim

 

[cwalden]

Wow. Fantastic explanation.thanks


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[az9133bm]

Brian is exactly right. Specifically, we can give you a recipe to follow for an R23.

This is our method to get on plane efficiently with a fully loaded/provisioned R23. Bear in mind that we cruise our boat typically on lakes at 3,700 ft. altitude (Lake Powell). Likely, you will not need as much RPM at sea level:

1. Tabs all the way up.
2. Engine trim all the way down.
3. Full throttle.
4. At 4800 rpm, both tabs all down quickly.
5. At 5100 rpm, trim up engine to show two bars on the Yamaha helm monitor.
6. At 5200 rpm (ideal cruise for our prop pitch), tabs up slowly as she planes but continue all the way up.
7. Use "starboard bow down" (it's the actual tab on the port side) to keep boat level due to induced engine torque.
8. Generally, we run with tabs up as much as possible. Passenger movements and sea state typically require minor adjustments, however.
9. If sea state allows, trim engine up two more bars.

Let us know if you have questions.

 

[stinson]

Perfect thanks guys so much.

With a 200hp engine, it seems she needs to run at higher RPM than I'm use to. Are these engines designed to run at 5200 RPM for extended periods of time?

 

[CruisingElvinRay]

We ran from Morehead City to Coinjock yesterday and the Albemarle sound was a beast. Mixed 1-2 ft seas. I used the trim tabs to keep the bow down during the crossing. More comfortable than bow up for sure.


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