Motor Timing

Adjusting the motor timing on modified motors is a common way to fine tune the motor for more RPM or torque. It is important to understand the limits of your motor when adjusting the timing, as you can quickly ruin the motor if you don't know what you are doing. Most motors should never have their timing advanced beyond 20-25°. Also setting the timing below 0° can cause serious heating problems and the motor to run backwards.

Advancing the timing gives you more RPM's and more power. However it does have some some side effects. These are: more heat, more commuator wear, and a shorter runtime. Decreasing the timing gives you more torque, longer runtimes, and less heating of the motor. It will also decrease the amount of wear on the commuator.

Adjusting the timing is similar, performance-wise, to gearing a motor. You can read more about that in my sections on Motor Gearing. Be sure to go into the section that deals with the truck you are using. Otherwise you may find yourself over or under gearing your motor.

Setting the motor timing isn't hard. Looking at the end bell of the motor, you'll see that it's just a circle. Like all circles fully around would be 360°. While 1/4 of the way around would be 90°. I've made notations that should were you should find 12°, 24°, and 36° on the image below. These should correspond to the marks on a Speed Gems 2 motor.

You can use the facts above to help determine what the factory marks are, or if you don't have any marks, to know how far you need to turn it. For a Speed Gems 2 motor each mark represents about 12°. The center of the double mark is 0°, while the third mark to the left of the 0° mark would be 36°. You should also be able to see a mark on the motor can. This is the timing mark, and is exactly in between the two opposing magnets.

To set the timing you simply turn the end bell counter-clockwise, until the mark on the can meets the degree you want the motor adjusted to. Then you tighten the screws that hold the end bell down. Remember that not all motors will have marks that represent the same amount of degrees as this example. Below is a Speed Gems 2 motor set to 24°.

Some motors have an actual timing strip printed on the label you can use instead of the notches on the end bell. Below is an example of one of these, a Speed Gems Pro. If you own a P-94, or any of several other Trinity hand wound modifieds, you'll notice they are very similar to this. While you can't see it in these pictures, there's a notch centered in front of the end bell screw that is the 0° timing mark for the end bell.

Looking at the label it can also be a little confusing as to which way to turn the end bell to advance the timing, since the timing strip goes both ways. You'll turn it counter-clockwise to advance, and clockwise to retard.

Here it is set to 0°...

...and here it is set to 10°.

With the Speed Gem Pro motors, one endbell screw will have a triangle shaped piece of metal under it. This "pointer" is what you use to set the degree of timing you want to have. It also helps ensure that you put the endbell back on the motor correctly after you disassembled it.

If you choose to get serious about setting your motor timing you can also purchase a timing jig such as the one offered by Trinity. It will allow you to set your timing much more accurately than the factory markings will.