1) Remove the bottom rotor cap. Take note of the outer rim of the rotor plate, and the actual rotor casing. There should be matching marks on each that line up exactly with each other. If these arent lined up perfect, you will not be able to successfully align the rotor. If they are out of alignment, you will have to remove the rotor screw and linkage, tap on the rotor stem lightly with a canvas hammer, or other soft hammer (non-metal) until the rotor plate pops loose. Make sure you have your hand underneath the rotor plate so it doesn't get damaged.

While you have the rotor out, you might as well clean it. Be careful with your rotor! The brass is very soft and the slightest bump on it can cause major damage. We sell several different brands of horn cleaning soap, and it does a great job cleaning rotors. After cleaning, dry the rotor well and use some of our "Slide-Bright" slide strips to shine up the rotor and the rotor plate. Lubricate the upper and lower rotor stem with some of our Super C key oil. Then, put some of our Super C rotor oil on the rotor itself. Insert the rotor carefully into the casing, making sure not to allow the upper spindle to touch the casing. This will keep the thicker key oil from getting on the casing, causing slow rotor action.

Once the rotor is inside the casing, turn the rotor plate until it is aligned with the outer mark(s) and tap the rotor plate down gently. The first rotor usually has a single mark. The second will have two marks, the third will have three, and the fourth will have four. This is done, so that you don't confuse the rotor plates when reassembing. You will need to spin the rotor stem with one hand while you tap the plate down with the other. This is to assure that the rotor spins freely. If the rotor plate is not tapped evenly all the way around, the lower rotor stem will "drag" on the rotor plate. Once the rotor plate is tapped in, you can then reassemble the linkage and tighten the rotor screw.

Look at the end of the rotor shaft. There is a well defined mark on it that runs half the diameter of the shaft. This mark acts as a pointer. This pointer should be very close to one of the two notches located on the rotor plate bearing itself. Depress the key and you will notice that the mark now points to the other bearing notch. These marks must lined up "perfectly". Otherwise, your horn will play stuffy. Take a razor blade and trim the rotor stop slightly until proper alignment is achieved. You may have to use a wider cork/neoprene and trim it down if the one you have is too small.

Lastly, screw the rotor cap back on. Some rotor caps have a tension screw in them. This will increase and decrease the amount of spin on the rotor and can be adjusted with a small precision screwdriver.