Tiller Handle outboard hard to steer left, Do I have a prop problem?

[mikmic2]

I have a 1986 35HP Force with a Tiller Handle for steering, on a 16 foot Jon Boat, with a wooden floor and two fishing platforms. With three people, two batteries, a trolling motor, and fishing gear in the boat, it goes about 20 MPH.<br /><br />Under full throttle I can steer the boat to the right, good enough, or at least acceptable enough for me, but if I attempt to turn the tiller handle to the right, which turns the boat to the left, it is extremely hard to do. So much that I back off the throttle, as it feels like I might snap the tiller handle off. I actually start sliding on the seat, trying to steer the goofy thing. <br /><br />I do not have a trim tab, or that little rudder thing on the bottom of the cavitation plate. All I have is a bolted on exhaust snout that isn't adjustable.<br /><br />I did notice that when I get up over half throttle, it appears that my throttle linkage will start to go out of center, at the hole where it goes through the bottom shroud, like the motor is turning on the mounts, and causing it to rub on the cowling, so I have to believe that the prop is causing the leg to turn so hard, it is twisting on it's rubber mounts. <br /><br />Would there be another prop I could go to, that would help with this problem? It seems to me I read something about a Cupped prop helping out hard steering problems to one direction. <br /><br />When I turn the prop over by hand, I do see that one blade looks like it it is closer to the gear housing, or the skeg, then the other two, but I didn't know if that could cause this or not. I didn't want to buy another new prop like I have, and still have the same problem. So I thought I should post here, to see if I should maybe get a cupped prop. Maybe they don't even sell a cupped prop for my engine. Could I have the mod added to a new prop? <br /><br />I'm baffled, and stumped.<br /><br />As always, any, and all help would be greatly appreciated.

 

[Justaboatin]

Re: Tiller Handle outboard hard to steer left, Do I have a prop problem?

I am not a "expert by any means" but I have a 18ft Jon boat (about 5 ft wide) with a 25HP Mercury Tiller with wood floors, and two fishing platforms. And with two grown men I get 26-28 Mph and with just me I push 30-32Mph. Mine does get tough to steer at full speed but very do-able. Is your motor too low? It sounds like there may be a issue... but that is based on my experince with mine.<br /><br />Hope that helps<br />Scott

 

[mikmic2]

Re: Tiller Handle outboard hard to steer left, Do I have a prop problem?

When you asked if my motor was to low, I looked and I suppose the cavitation plate is about 1-1.5 inches below the rib that runs down the middle of my boat. <br /><br />I measured my transom and it is exactly 21 inches tall. But right in the center I do have a rib which adds another inch or so. It appears that my engine is about 23 inches from where it rests on the transom to the cavitation plate.<br /><br />Do you suppose that 1 inch or so would make that much of a difference? <br /><br />Should I raise it until the Cavitation plate is even with the bottom of the boat and forget about that rib that is about 3/4 inch wide and 1 inch tall?<br /><br />You might be on to something, maybe this is a lot of my problem. <br /><br />If I forget the rib, I can get it up another 2 inches, it looks like. Would this help that much?

 

[Justaboatin]

Re: Tiller Handle outboard hard to steer left, Do I have a prop problem?

From what I have heard in the past, Your cavitation plate should be a little higher then that. I am pretty sure it should be flush with the bottom of the boat. At full speed my plate is pretty much out of the water. Hope you are in the right direction!

 

[mikmic2]

Re: Tiller Handle outboard hard to steer left, Do I have a prop problem?

Well, we've finally got a easily steerable boat in both directions.<br /><br />The main thing I believe was at the bottom of the steering pin, on the leg are 4 bolts. Two that go all the way from one side to the other. Well it was missing one, and the other one was loose, so the leg wasn't clamped tight to the pin that goes through the transom bracket. There was also two other bolts down there that were quite loose, as well. I think that was also causing the throttle linkage rubbing on the cowling, at higher throttle, as the whole leg was twisting.<br /><br />The second thing I did, was raise the motor 2 1/4 inches. <br /><br />The last thing was a friction plate or whatever you call it. It is an adjustable tension for the steering. It is almost like a half moon brake shoe, and you adjust the bolt which takes care of pad pressure. I didn't see it because it is underneath the cowling right tight to the transom bracket, but you really have to look for it.<br /><br />What I think was happening, was because the leg wasn't attached to the pin real tight, when you gave it throttle, the motor was twisting on that bottom mount, causing the engine to rub on that adjustable friction plate harder. This way if you tried to steer the boat to the left, it caused more pressure on that plate. But when you were turning right, the pad was going down hill, so to speak. It was actually getting tighter the more you tried to steer to the left, while under half or more throttle. <br /><br />Bottom line is, now that I did all that, I can actually veer back and forth with relative ease. <br /><br />I guess I didn't think of looking for loose bolts, as my problem was tight steering. Who would of thunk loose bolts? Not me. LOL<br /><br />So, I guess it wasn't a prop problem after all. <br /><br />I also gained about 3 miles an hour, which was probably from raising my engine up.<br /><br />Thanks justaboatin, roscoe and rit for the replies.