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The problem with a motor mounted to the side.

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indecentseas
1st Mate

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Canada
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Initially Posted - 04/02/2014 : 18:23:45

I'm hoping some of you might have a helpful suggestions. I'm having troubles setting off from the dock.

My outboard engine is mounted on the port side of the transom. My moorage is typical. I am in a long line of boats that nose into a spot and sit perpendicular to the lane of travel. When moored my boat faces north. The lane of travel behind me goes West. The wind and current are generally from the West.

To get out of my slip I back up and turn the boat 90 degrees to starboard (I move the stern of my boat to east so it faces west). I generally don't use the engine to do this. I just push the boat off the dock and steer with the tiller. So far so good. I can usually get the boat perfectly aligned, perpendicular to my starting position. The problem is when I try to start moving forward. I've usually got a bit of backwards momentum. As soon as I engage the motor to go forward the boat kicks sharp to starboard, try as I might to direct the boat with the tiller. The reason is of course that my outboard is mounted on the left side. After a few seconds, as the engine has the boat moving forward the tiller starts to counteract the steering influence of the motor and I can straighten up. Sometimes I can get out without assistance but quite often I need someone up on deck near my bow to push off boats on my right side.

I'd really like to get this routine down. Sometimes I am able to get out without help, sometimes a little push works, but every so often it all goes to **** and my boat can end up 90 degrees off the desired angle and I need several helping hands to straighten out. I'd like to be able to reliably get my boat off on its own so I can do an occasional solo trip.

I can't tell what effect tide and current may have. I just know I get more stressed when they are stronger.

Is there a reliable way (short of installing a bow thruster) to get the boat to steer straight during that time it changes from moving slowly backwards to slowly forwards?

Thanks!

David Hopkins
Vancouver, British Columbia
'78 Swing Keel, Standard Rig, Dinette
#534

Edited by - on

Stinkpotter
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Djibouti
9013 Posts

Response Posted - 04/02/2014 : 18:35:10

An obvious question is whether you're steering the outboard somewhat to port to get started. The perhaps less obvious option is to turn the opposite direction and back out of the fairway. I've done that in some tight situations. The trick is to steer carefully with the rudder, which will try to kick over to either side while you're backing.

When you say "kicks hard to starboard" do you mean the stern pushes to starboard? That would be prop-walk from the outboard in forward gear. Try turning to starboard, give a burst, throttle back, and use the rudder to line you up. Then throttle up slowly. Prop-walk is worst when the boat is moving opposite to the thrust (like backward) or not at all, and more thrust creates more prop-walk.

Edited by - Stinkpotter on 04/02/2014 18:42:32

indecentseas
1st Mate

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Response Posted - 04/02/2014 : 19:19:50

Dave,
When I say kicks to starboard I mean the the bow goes to starboard. My outboard is fixed in place on the port side and does not rotate. Without anything else steering the boat the engine alone will turn the boat to starboard. But I had not considered prop walk. I'll look into that and try. I'll also try your suggestion

Backing out is not an option.

Thanks.

Edited by - on

Steve Milby
Past Commodore

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Response Posted - 04/02/2014 : 19:26:08

Dave is right. The problem isn't caused at all by the offset motor. It's prop walk. Whenever you put most boats in forward gear and open the throttle, the stern will kick to the right. The solution is that you need to back much farther away from the dock before you put the engine in forward gear. Then, you should open the throttle enough to accelerate fairly quickly. The reason is that the rudder won't have any affect in steering the boat until the boat is at a speed that is fast enough for the boat to have "steerageway." If the boat has steerageway, then it will respond when you put the tiller over. By backing farther away from the dock before you put it in forward gear, you give the boat enough distance to gain steerageway and to turn the boat before it hits the dock. If the wind is blowing hard when you back out, you will need to back even farther out, because the wind will make it a little harder to gain steerageway.

It's also possible that your engine is turned slightly to the right, which would drive the boat to the right. I can tell you, though, that all C25s have the outboard slightly offset either on the right side or on the left side of the transom, and we can all tell you that the slight offset of the engine doesn't appreciably interfere with the steering of the boat.

Question: What kind of motor do you have, and why doesn't it rotate? I can't recall seeing an outboard motor that can't be turned so that you can direct its thrust. I wonder if the steering shaft might be frozen up.

Edited by - Steve Milby on 04/02/2014 19:44:39

Voyager
Master Marine Consultant

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Response Posted - 04/02/2014 : 20:14:18

Last winter an extended seminar was discussed, and a URL was provided, for a highly detailed and extensive docking course.
[url="http://www.catalina-capri-25s.org/forum/topic.asp?TOPIC_ID=27761&SearchTerms=docking"]Docking Techniques Seminar[/url]
I don't recall all of the details, but there was a great deal of discussion about using spring lines and dock lines to put the boat into position off the dock. The matter of lining up the boat to anticipate and compensate for prop walk ahead of time was a major point of discussion.
For example, if you know that before you get under way, prop walk will spin the boat 60 degrees with respect to perpendicular, it may be possible to anticipate the degree of rotation, the starting and ending position of the boat and the amount of "translation" needed by the boat to compensate, and to avoid hitting other boats given 0 wind. Then the calculation should be extended to compensating for breezes and currents.

Edited by - Voyager on 04/02/2014 20:22:48

indecentseas
1st Mate

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Canada
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Response Posted - 04/02/2014 : 20:29:10

Steve, the outboard is a Yamaha 8. The mechanism that attaches to the boat can be hoisted up to get the engine out of the water. Alternatively, there is an electric motor that can rotate the engine out of the water (i.e.: the engine head rotates down and the prop comes up). I will have a closer look but I have not seen anything that would allow the engine to be angled left or right.

Edited by - on

Stinkpotter
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Djibouti
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Response Posted - 04/02/2014 : 20:34:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Steve Milby
 Dave is right. The problem isn't caused at all by the offset motor. It's prop walk...
<hr height="1" noshade id="quote"></blockquote id="quote">Well now I'm not so sure... In forward gear, prop walk pushes the stern to starboard, so the bow to port. You report the opposite. However, the side of the transom is unlikely to be the reason, because the motor is only about 1.5' off centre, about 12.5' from the pivot point of the boat. I think I'd have to be there...

But like Steve and Don, I'm wondering why you can't turn the motor. It would seem that turning it to port (handle to starboard) would direct thrust to counteract whatever is happening. But to be honest, I still wonder if your stern is being pushed to starboard in forward gear while drifting backward or standing still. In that circumstance, I would completely expect it. (Maybe you have a left-handed prop. But I seriously doubt it.)

If you have a steering damper, you should be able to ease it enough that you can turn the motor when you want, but it will stay centered when you want. I set the damper so I could easily turn the motor when I wanted to (which was only when backing into my slip), but the motor would stay where I set it, including when centered so I could just steer with the tiller. (Prop-walk actually helped my turn to port when going forward out of my slip.)

Edited by - Stinkpotter on 04/02/2014 20:51:17

Steve Milby
Past Commodore

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Response Posted - 04/02/2014 : 20:54:42

It looks like the motor is mounted without the tiller arm attached to it, which is a little unusual way of mounting, but it's ok. But, there should be an adjuster that can be loosened, and that permits the engine to be turned left or right, and then it can be re-tightened. I think Dave is still right, but for a different reason.

Edited by - Steve Milby on 04/02/2014 20:55:51

Stinkpotter
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Djibouti
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Response Posted - 04/02/2014 : 21:04:15

Whoa... No tiller handle on the motor?? That sounds like an outboard intended for a power boat with wheel steering. I think you might have a strange mismatch there. You must have the throttle and shift in the cockpit... That's an "interesting" option, but not what I would recommend on a C-25. You have some of the characteristics of an inboard, without the benefit of having the prop in front of the rudder.

Steve should take it from here...

Edited by - on

Stinkpotter
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Djibouti
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Response Posted - 04/02/2014 : 21:24:40

However, I have a question about your setup: When you're motoring at a normal speed, can you hold a straight course with the rudder centered? If not, you should be able to turn the outboard by twisting the power-head to an angle that makes your steering neutral (and effortless) at speed. I'm not saying this will fix your zero-speed maneuvering issue, but it might make life just a little nicer. Most of us make that adjustment with the outboard's tiller handle without thinking about it.

I wonder if a Yamaha dealer can retrofit a tiller handle for you. Yamaha has a nice long handle with the gearshift on it--an ideal setup for a boat like this. I think you want it for maneuverability around your slip.

Edited by - Stinkpotter on 04/02/2014 21:26:03

Steve Milby
Past Commodore

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Response Posted - 04/03/2014 : 08:04:07

If you can't turn the motor on a C25 and aim it's thrust in a certain direction, you lose much ability to maneuver it. If the boat is always kept on a mooring, that might not be too much of a problem, but if you need to maneuver around docks, then the only way you can make tight, low speed turns might be by using spring lines and/or by having a crew member fend the boat off of pilings and other boats. I'd have a tiller arm installed, so you can turn tnhe motor.

Edited by - on

GaryB
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Response Posted - 04/03/2014 : 09:34:25

Looking at the picture you can see the sthrottle and shift cable running into a boot on the transom but no tiller handle.

If you can't get a tiller arm installed by the dealer you can build an arm that bolts to the small arm that sticks out below the powerhead on the front of the engine where the steering cable on a normal powerboat would attach.

Sounds complicated but it's not.

Edited by - on

pastmember
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Response Posted - 04/03/2014 : 10:02:41

You are dealing with the result of a bad application of motor, mount and controls to a sailboat. Is the motor an EXTRALONG?

Edited by - pastmember on 04/03/2014 15:36:59

JohnP
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Response Posted - 04/03/2014 : 11:24:49

I'm not surprised by your problem. You said you back out of the slip into the fairway (supposedly with the engine running in neutral), turn the stern downwind (to port) and with the bow heading upwind in the fairway you shift to forward and start moving.

Your boat is barely moving forward, but is still rotating to starboard. The bow is also heading into the wind, and the combination of the initial rotation and wind catching the bow makes the bow continue to turn to starboard towards the other boats across the fairway before you get going. That's no good!

I can think of a simple solution. Your need to develop steerageway sooner. Why don't you try shifting to forward gear when the bow has turned only 45 degrees? You said you had the boat "perfectly aligned", but our boats are big, clunky floating things that have a lot of linear momentum and also angular momentum when turning at slow speed. Once they do turn at low speed, they don't stop turning, unless they are moving forward at more than 1-2 knots. I assume you have the swing keel all the way down, because that helps with developing steerageway, too. The boat rotates more easily with your keel up.

You can practise this kind of turn out on the open water, to become more familiar with it. The "perfectly aligned" angle may be 45 degrees or 60 degrees away from your final direction before you move forward.

The other discussion about your outboard's tiller is also important, but you may not need to fix it to solve this problem. Personally, I use my outboard's tiller together with the boat's tiller to turn the sharpest in tight spaces, like when backing into my slip. I have the same situation in my marina, and I choose to motor forward out of the slip and turn to port down the fairway.

Happy sailing!

Edited by - on

Sloop Smitten
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Response Posted - 04/03/2014 : 17:39:59

Haven't heard it mentioned in a while but wouldn't a soft-link help overcome the steering problems?

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dlucier
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Response Posted - 04/03/2014 : 18:13:10

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Sloop Smitten
 Haven't heard it mentioned in a while but wouldn't a soft-link help overcome the steering problems?
<hr height="1" noshade id="quote"></blockquote id="quote">

When backing out of my tight slip, I at times have the outboard and rudder tillers hard over in opposite directions for greater maneuverability.

Edited by - dlucier on 04/03/2014 18:14:28

Stinkpotter
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Djibouti
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Response Posted - 04/03/2014 : 18:37:34

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by dlucier
 When backing out of my tight slip, I at times have the outboard and rudder tillers hard over in opposite directions for greater maneuverability.
<hr height="1" noshade id="quote"></blockquote id="quote">I presume you mean when the boat is still moving backward and you're applying forward thrust to pivot it. I've done the same thing to do a pivot essentially in place.

Edited by - on

WesAllen
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Response Posted - 04/03/2014 : 18:49:32

My Mercury 9.9 extra long shaft Big Foot came with no tiller handle. It did include controls for a somewhat steep price which works really well on mine. It does have lever that locks and stops the pivoting. Loosen it and it is easy to twist the motor in the needed direction. When maneuver is finished simply lock the lever again. But I will admit that it could use a small tiller handle for leverage sometimes. Not for the controls but for steerage.

Wes

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dlucier
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Response Posted - 04/03/2014 : 20:09:49

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Stinkpotter
 <blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by dlucier
 When backing out of my tight slip, I at times have the outboard and rudder tillers hard over in opposite directions for greater maneuverability.
<hr height="1" noshade id="quote"></blockquote id="quote">I presume you mean when the boat is still moving backward and you're applying forward thrust to pivot it.
<hr height="1" noshade id="quote"></blockquote id="quote">

Yes. While still moving backwards, I turn the outboard hardover directing the thrust to help kick the stern over quicker, slow rearward momentum, then transition to forward movement.

Edited by - dlucier on 04/03/2014 20:14:12

Dave5041
Former Mainsheet Editor

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Response Posted - 04/03/2014 : 20:43:56

Everything is variable, but I back out of my slip and start my forward quick burst of throttle at about 60 degrees. I then turn the motor and idle forward until straight. How much throttle and timing vary with the breeze. I don't know where Yamaha puts their rotation lock, but all commercial outboards rotate. Steering a powerboat would be impossible without rotation since they don't have rudders. I don't think you can mount a standard throttle tiller with remote controls, so a shaft adapted to simply turn the motor would probably be your only option, and it would definitely be cheaper.

Edited by - on

dlucier
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Response Posted - 04/04/2014 : 11:11:16

Adding a tiller to his outboard may complicate the maneuvering issue further in that he'd have to dance between the outboard tiller, rudder tiller, and the cockpit outboard remote controls.

Edited by - on

Captain Max
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Response Posted - 04/04/2014 : 20:09:28

Two comments, are we assuming the rotational spin of the prop? It could be opposite direction which would make the prop walk opposite. I always back into my slip (which has its own problems) makes it a breeze to get out.

Edited by - on

indecentseas
1st Mate

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Response Posted - 04/04/2014 : 22:09:44

A few updates:
-My propeller is right handed so prop walk does not explain my problem. Prop walk should draw my stern to starboard, the opposite elf my problem
-With my current mount I cannot see a way to rotate my motor. I will make inquiries. I have included some other pictures of the setup.
-backing in to my spot is not possible.

I am pretty sure the problem I'm having (my boat turns to starboard when I initially start moving forward) is caused by my motor being on the port side of the transom (it's mounted quite far to fort and extended some distance from my boat.)

Perhaps there is no easy solution to my problem, short of a different mount for my motor.

I appreciate all the suggestions.

Edited by - on

Kim Luckner
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Response Posted - 04/05/2014 : 07:52:53

I think what you want to do is cancel out the "prop walk". The lever show in the picture is meant to allow you to "lock" your motor off center. Set this when you can balance the thrust with the rudder in a straight channel. Same as Wes suggested. This assumes you do most/all of you steering with the rudder. http://www.yamaha-motor.com/assets/service/manuals/1/LIT-18626-07-17_1378.pdf

Picture on Page #19 shows Steering Friction Adjuster

Edited by - on

Stinkpotter
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Djibouti
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Response Posted - 04/05/2014 : 09:29:26

I'm afraid David is right: prop-walk doesn't explain his problem. And from the first photo above, it looks like the outboard is set to push the boat slightly to port, as if to compensate for its being mounted on the port side. The only real solution for zero-speed maneuvering is to be able to turn the outboard. I'd talk to a Yamaha dealer and, if necessary, lose the cockpit controls in favor of Yamaha's long tiller handle with the throttle and shifter on it. That combination is easy to use from the cockpit, and eliminates some tripping/bruising hazards in that narrow space.

What was a cool setup for one P.O. turns out to be not so great for David. There's a reason almost all of us have (or had, in my case) tiller-operated outboards on our C-25s. Some C-250 owners with wheels have linked their outboards to their rudders, but that's a somewhat different situation. With my tiller steering, I preferred independent outboard steering for a few reasons, one of which Don so clearly illustrated above.

Edited by - on

pastmember
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Response Posted - 04/05/2014 : 18:22:51

I think Dave spotted it. The motor is aligned perpendicular to the radius of the stern and not parallel to the rudder. Take Dave's advise and change your set-up.

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