boat twists to left

[rastoga]

I just installed a teleflex rotary no feedback steering system on my boat. Everything is great but at top speed the boat twists to the left. It doesn't really turn to the left, but the port freeboard is less than the starboard at the upper rpms. It didn't do this before with the old rope and pulley system. Is it possible that the prop torque is being transferred to the boat itself since it is locked out of the steering wheel? I have a plywood runabout with a 40 hp yamaha. I suppose this is possible since the boat is lightweight. Does this make sense? Has anyone else had any problems with NFB systems? Is there anyway to correct this with the trim tab or anything?

 

[steelespike]

Re: boat twists to left

It sounds like you are talking about prop torque.<br />Im no Physics expert but prop torgue should be the same regardless how you steer.If you sit on the stardoard side it would seem your weight <br />would counterbalance the torque. I dont run a<br />steering wheel.If the steering cable runs down the port side would it add enough weight to make the torque show. You didnt move the motor and not get it back right did you?

 

[almost retired again]

Re: boat twists to left

Rastoga,<br />Turn the trim tab in the direction of pull, as viewed from the rear.<br />Hope this helps

 

[rastoga]

Re: boat twists to left

The boat is twisting to the port, i.e. the port gunwale is closer to the water at high prop RPMs. What's a little weird is that it still goes in a straight line. I suppose that's the no feedback system keeping it on course. <br /><br />As far as I know I have 3 adjusment options, where the motor is mounted on the transom, the angle of the trim tab, and weight distribution on board. Is that right?<br /><br />transom mounting-<br />I noticed my motor is mounted about 1/8th of an inch to the port of dead center. Would it help if I slide the motor over to dead center or even past center towards the starboard? <br /><br />trim tab-<br />If I understand correctly I should turn the trim tab over to the port side to help correct the port twisting.<br /><br />weight distribution-<br />My boat is balanced at the dock and while underway at slower speeds. It only lurches to the port at higher speeds. Everything but the fuel tank is already mounted on the starboard side. The steering cable, battery box, helm, etc. I suppose I could move the fuel tank over too.<br /><br />Please tell me if I'm out of line on any of these or if there is anything else I could do. I'm really curious as to why this never occured until I installed the new steering system.

 

[Hooty]

Re: boat twists to left

Hey rastoga,<br />I think I might be asking the nice folks at Teleflex if they have an answer. If you contact them, let us know what they say.<br /><br />c/6<br /><br />Hooty

 

[steelespike]

Re: boat twists to left

I still cant see the new steering causing the problem.unless your boat is tiny I dont think you would have a torque problem.I think something<br />has happened to your hull since you last used your boat.Examine the bottom carefully.I think you said it is plywood you may have some sort of distortion in the bottom, wouldnt take much.. With the boat on the<br />trailer check from all directions and angles<br />look for a twist or hook.<br />Gotta wonder if you have everything on the starboard side why does the boat appear balanced<br />at rest.I dont think moving the motor will help,<br />also trim tab.The only boat i have ever driven with noticable prop torque problem is my 1929 inboard and they put the steering wheel on the port side. When alone I have to sit toward the centerline to level the boat. I really think <br />problem is with the boat not the motor or steering. Check it all over carefully youll find something.

 

[Tracy Coleman]

Re: boat twists to left

rastoga<br />I don't think that the steering has any thing to do with your problem. You mentioned you have a light plywood boat, I would suspect that a "powerhook" in the bottom might be closer to the problem. If the trailer improperly supports the boat with the bunks or keel rollers, this will cause a problem. If the homebuilt boat is not strong enough to hold the boat bottom straight at higher speeds, you get all kinds of squirrely performance. If you didn't change the location of the helm, the seat, fuel tank, battery, install a windshield, tilt/trim angle, I put my money of the boat being the problem.<br />Backfire