How to use Trim Tabs and PTT

M

Mike_J

New member
hello all, as a new CD22 user, I am learning quite a bit about boat handling as it handles very differently from my old 16ft welded aluminum!
I would greatly appreciate any pointers to a post or article elsewhere on how to best adjust the motor trim and the trim tabs on a CD22.
My CD22 has trim tabs with a pair of rocker switches in the dash and a pair of Yamaha 50 HP motors.
 
Mike,

What I generally do is make the "major" adjustment to the engine position using the motor's trim feature and the trim tabs for the minor (precise) adjustments. For now, leave the trim tabs in the fully retracted position; you'll get to them later. Play with the motor trim a bit, and with some experimenting you will find what seems to be the best combination of engine trim and resulting speed (which will vary with loads and sea conditions). To begin, you will probably want to experiment with the engine trim adjustment at about it's neutral setting. Remember - trimming the motor 'down will help you get on plane, but probably not your most advantageous position. Again ... experiment, experiment, experiment. I even found that it's good to make some notes - to help me remember the next time "what seemed to work best."

Once you're comfortable with engine trim move on to experimenting with the trim tabs. Set up the engine in the optimum configuration and now, begin adding-in some trim(tab). For now, use both trim tabs together. Add a little, then add some more. Notice how the pitch attitude of the boat changes. More and more trim tab will bring the bow down - you'll see/feel the difference. (Be a little careful if you add full trim tabs at high(er) speed; you could bring the bow down farther than you were expecting!

If you have a fuel meter, watch the gph and boat speed. with some playing around you will find that "sweet spot" that yields the best speed at the lowest RPM with only the (least) necessary amount of trim tabs. (Remember - on plane the trim tabs themselves will induce increasingly inefficient 'drag, so this is a case where less-is-better.)

As you become more comfortable with your trim tabs you will find them to be very useful. If your boat is unevenly loaded you can correct it (somewhat) by using different tabs setting on port or starboard.

Best,
Casey&Mary
 
There are two uses of the trim tabs:
1 to trim from side to side, according to load in the boat, and wind pressure/seas etc.

2. To trim the bow down into heavy head seas, or to bring the stern up if in following seas, to avoid "bow steering"

I generally give a little of the trim tabs to bring the boat up on a plane faster.

I leave the outboard in the center of the trim gauge to start with. Leave the throttle setting alone. Move the outboard up and down, until you get the maximum speed for that throttle setting. That is your most efficient speed.

After the motor is timed properly, you may want to move the trim tabs slightly to account for balance/trim and sea conditions. Again watch the RPM of the engines. If they go down, then you have trimmed down too much by the bow--unless you want to do this because of chop.

For heavy head chop, I recommend putting on permatrims. I have had bots with and without--the boat does better in head seas, with the Permatrims.
 
thataway":uw9hpjbx said:
There are two uses of the trim tabs...

2. To trim the bow down into heavy head seas, or to bring the stern up if in following seas, to avoid "bow steering"
Click to expand...

This will be my first boat with trim tabs (and Permatrim), so I'm reading this thread with interest. Thataway: In the second half of your point #2, do you mean "to bring the stern down"? Or is it correct as stern up (bow down) for both cases (head seas and following seas)?

I just wanted to check if it was an inadvertent mis-type because I was thinking it would be bow up to avoid bow steering, but then I don't really know (yet!).

Sunbeam

PS: Have the Permatrim installed; trim tabs yet to go. For some reason, drilling into that pristine plate on the Yamaha was a lot harder for me than drilling into fiberglass :shock:
 
I like to use the tab and the motors for two different things. Now you can adjust the bow up /down angle with the trim tabs but I prefer to do that with the motor trim instead. I use the tabs to adjust the left right balance of the boat. I don't like a boat that leans.

Use the motor to trim your bow for the best ride and mileage for the conditions you are in. As other's have stated, you can trim down the bow to smooth out a ride in chop or you can raise it up to get better speed and mileage from a set RPM. Listen to your motor and feel the boat luke. People often ask 'what is the right angle on the gauge" Don't know I never look at the gauge , I just feel the boat and listen to the motor. You want to avoid the prop slipping if you are trimmed up to high. Your motor will rev up with out input from the throttles. Once you hear it you need to trim down until it stops. In big waves or following sea it may come and go as you pass over a wave. Either slow down or trim down.

Now I use the tabs to trim the boat from left to right depending on the load and the sea's. Flat bottom boats tend to lean in to a swell from the side. So I will trim that side up a little to keep the boat flat. Also useful for heavy loads or when you have two or three guest on board.

As others have said just go use the boat and play with it. Best teaching tool it doing.
 
Thanks - I was following it through in my mind and guessed it was probably a mis-type, but... figured I'd check.

Got the HPU mounted.... next come the tabs themselves.

Sunbeam
 
Mike, like others have said experiment to see how different trim angles affect your ride, steerage, fuel economy, and hull posture in the water.

In Lake Erie, because of the chop I find I cannot trim much bow up into a sea. On the other hand in a following sea you have to trim up especially when running at speed. The first year we had our Stingray, we were going from Port Dover to Port Colborne(53 miles) in a following sea. We were running about 35mph - taking spray over the windshield, but it was a hot day so it was keeping us cool. Not sure now if I was playing with the trim, hit a stacked wave, or was going too fast for the conditions - but I stuffed the bow and took a lot of "green" over the top. :shock: That is not the most fun thing you can experience on a boat!

Keeping the drive leg down when your coming into a marina or channel will give you better steerage. If you get caught off plane in weeds, you can trim up till the prop is just below the surface and go slow. If your prop gets fouled, reverse and throttle. Do not run a stern drive at full power or any speed with the drive leg at a steep angle. This puts intense strain on the U joints.

Regards, Rob
 
Back
Top