Bravo Steering Problem?
06-19-2003, 08:51 AM
#1
Guest
Posts: n/a
Bravo Steering Problem?
When I go out of the hole, my steering wheel wants to pull hard to the left. It pulls hard enough that my wife is scared to drive the boat. Once on place, it drives straight and true and you never need to touch the wheel.
I will add that I have a nose cone and when on the trailer, the steering has no play and the drive will move its full range with little or no resistance. Also, it has the flat non fin zinc.
Any idea?
I will add that I have a nose cone and when on the trailer, the steering has no play and the drive will move its full range with little or no resistance. Also, it has the flat non fin zinc.
Any idea?
06-19-2003, 09:34 AM
#2
Do you have big HP, power assist steering? Singles pull and as you add HP then it becomes more pronounced. If your steering is just a cable with no power assist then your really going to feel it.
Just one more check. With the bravo held in place on the trailer, see if you have play in the steering. If you do you have a bad tiller and most likely need a new gimbal ring.
Just one more check. With the bravo held in place on the trailer, see if you have play in the steering. If you do you have a bad tiller and most likely need a new gimbal ring.
06-19-2003, 09:41 AM
#3
Guest
Posts: n/a
Followup info
There is no play in the steering, gimble, tiller, everything is 100%. It is all mercruiser, power steering, 300hp 7.4. Yes, as I add power the pull is more pronounced until on plane and then it all goes away. Is there some sort of adjustment in my power steering?
06-19-2003, 05:25 PM
#4
You may want to drive a couple other boats with single BB engines to compare.
If it pulls left put some left tab down to try to compensate.
I'd try reversing the rotation of the prop (borrow a another first). The Bravo will spin either direction. Here is some techno stuff if you into it. Same effects as airplanes.
1. Engine Torque Reaction. If the propeller rotates clockwise (when viewed from the rear of boat), the torque reaction will be anticlockwise. This will tend to rotate the boat in the opposite sense, i.e. roll to port.
2. Asymmetric Blade Effect. In level cruising the distance traveled by the up-going and down-going blades in half a revolution are equal. However, at the beginning of planing the boat is in a bow up attitude, when the axis of rotation is no longer the same as in the horizontal path of the boat. This produces asymmetric blade effect. The down-going blade now has to cover a greater distance than the up-going blade in the same amount of time (1/2 rev), so its relative water flow is faster. At the same time the angle of attack of the down-going blade is greater than that of the up-going blade. Therefore the down-going half of the propeller will be generating more thrust than the up-going half, which will tend to yaw the boat to port propeller axis of rotation is bought in line with the boat's horizontal path.
3. Gyroscopic Effect. As the boat goes on plane, a force is applied to the top of the propeller disc. By the laws of gyroscopics, this force acts as although it was applied at 90ŗ in the direction of rotation, which will produce a swing to port.
In boats which have propellers that rotate anticlockwise, all these effects will be reversed, and those fitted with contra-rotating propellers, or two propellers turning in the opposite direction will experience none at all.
If it pulls left put some left tab down to try to compensate.
I'd try reversing the rotation of the prop (borrow a another first). The Bravo will spin either direction. Here is some techno stuff if you into it. Same effects as airplanes.
1. Engine Torque Reaction. If the propeller rotates clockwise (when viewed from the rear of boat), the torque reaction will be anticlockwise. This will tend to rotate the boat in the opposite sense, i.e. roll to port.
2. Asymmetric Blade Effect. In level cruising the distance traveled by the up-going and down-going blades in half a revolution are equal. However, at the beginning of planing the boat is in a bow up attitude, when the axis of rotation is no longer the same as in the horizontal path of the boat. This produces asymmetric blade effect. The down-going blade now has to cover a greater distance than the up-going blade in the same amount of time (1/2 rev), so its relative water flow is faster. At the same time the angle of attack of the down-going blade is greater than that of the up-going blade. Therefore the down-going half of the propeller will be generating more thrust than the up-going half, which will tend to yaw the boat to port propeller axis of rotation is bought in line with the boat's horizontal path.
3. Gyroscopic Effect. As the boat goes on plane, a force is applied to the top of the propeller disc. By the laws of gyroscopics, this force acts as although it was applied at 90ŗ in the direction of rotation, which will produce a swing to port.
In boats which have propellers that rotate anticlockwise, all these effects will be reversed, and those fitted with contra-rotating propellers, or two propellers turning in the opposite direction will experience none at all.
