motor pulling boat to the right

[matt194]

I have a 14.5ft tri-hull glastron with a 1979 Evinrude 115hp. I have been fixing up the engine and boat and I beleive I have one cylinder that isn't working. Now to the problem, when I was driving my boat today I noticed that it wants to pull to the right really hard. I mean if I were to let go of the steering wheel I would do small circles in the water. I don't know what would cause this but I do have a prop that is somewhat beat up. Do I have to align the motor or prop. Can someone help me please?

Here is my webpage so you can see my rig, if it helps.
http://www.webpages.ttu.edu/matpope/boat.htm

 

[jddenham]

Re: motor pulling boat to the right

You do need to use a prop in good order, but that shouldn't affect your steering as such.

You have a big motor on a small boat, it could be heavy torque steer?

At the back of the AV plate above the prop is an anode fin that can be used to get a baseline for direction to some degree, you might adjust that 20 degrees or less and see if it makes a difference.

As far as one cylinder not firing possibly - have you adjusted your idle to 1000 in your driveway? (should be 600 or so when you get to the river).

Have you checked the plugs for uniform colouring after running it? One out of color might indicate a non firing cylinder.

Have you done a spark check?

Have you done a compression check?

Once again, that is a very large motor for that boat. If you don't have a 23+ pitch prop you run risk of over revving the motor.

 

[Dhadley]

Re: motor pulling boat to the right

With the motor mounted all the way down like that you will have a lot of steering torque. Naturally your prop has a lot to do with what mounting height you'll end up with.

If the steering pulls to the right, move the fin to the right. Once you get things running correctly you may want to try and locate some of the Turbo Pro IV props. They should work well on that rig. When you're ready, contact me if you like at dhadley50@aol.com.

 

[Chris1956]

Re: motor pulling boat to the right

Matt, Does your boat have a 15" transom? Most boats of that length do. Your motor appears to be a 20" shaft length. If so, and the motor's Antiventilation plate hangs 1 inch or more below the hull, that will cause your problem. If that is not the issue, set the trim up a hole. Boats will pull right if the motor is trimmed in too much.