View Full Version : Breaking in a stock motor.

2014.06.18, 09:05 AM
This tutorial isn't purported to be the do all super duper method for breaking in a stock Kyosho MZ9 motor but it is highly effective. it was passed to me by one of our own and as far as I am concerned our premier motor builder for this scale.

When I had a need for a solid performer for stock class racing I consulted with member flash2p for a procedure that would give performance and longevity to the oft maligned MZ9. I followed the procedure to the letter and it has provided me with a motor that has seen a couple years of use with very good performance and un-paralleled reliability with absolutely no overheating issues.

Step one: Source a reliable 2.4V power source. Be it Motor Master or a hand full of AAA's to use a pair at a time.

Step two: Submerge the motor in an adequate sized container of clean water then connect to the power source and let it run for a full four hours. This is easier with the Motor Master but if you like swapping out batteries the other way works just a well. The applied voltage is important so don't get impatient and bump it up for a shorter duration. Your patience will be rewarded.

Step three: at the end of the four hour run in, remove the motor from the water and let drain(basically drip dry) until there is no longer water dripping from the can. At this point a stable fairly high pressure air supply is needed to blow out the remaining moisture.

Step four: THIS IS IMPORTANT!! Hose out the motor thoroughly using ONLY T.A. Emerald Industries Performance Plus.4 motor cleaner. There is nothing available that is close to this product for what we use it for. Once the motor has been hosed out with the Plus.4 let it air dry. As a side note the Plus.4 will not damage any plastic parts of the Kyosho chassis(no color changing or embrittling) or paint damage to your hand painted beauties.

Step five: Using Glidex high speed Aerospace synthetic lubricant for BRONZE BUSHINGS, apply a very small drop to the needed surfaces. At this point the motor is ready for use. If you think you need more, once the motor is installed in the car, very carefully add a miniscule amount through the little "smiley" shaped opening on the endbell of Bachman E-Z Lube item #99981. The results will astonish you. Be prepared though for a marked reduction in drag brake action on throttle release.

Since the majority of us run on RCP circuits of limited size there is no use in trying to pull anything but a 6 or 7 tooth pinion. Keeping the pinion small reduces load heat build up in the motor and helps promote magnet life in an already limited product not to mention the effects of the high heat on the plastic chassis components. For a satisfactory heat test to see if you are trying to pull too high a gear just run the car for what is equivalent to a heat race. Then touch the motor to your lower lip. If you can hold it there you are geared correctly. If it instantly raises a blister first seek medical attention and then install a smaller pinion.

The products mentioned here gave me the results that I needed and have kept the motor in fighting trim since the procedure was completed. Use what you want or have available but don't expect the same results even though they might be the same. I'm not trying to promote or "dis" any specific product. I am merely passing along or handing down what has been given to me.

See you at the races

2014.06.18, 11:54 AM
thanks for the written procedures. certainly worth the effort if it extends the life of a stock motor and reduces heat build up. I'm ordering Plus4 from threw hobby works to avoid shipping of hazardous materials and already have the Bachman E-Z lube.

if anyone at Hobby Works needs help with this, please let me know as i would prefer all of us use this method to help maintain stock class motors.

2014.06.18, 06:36 PM
Thanks Mike. :)

2014.06.18, 09:23 PM
I used a very similar method when I was racing 1/12 scale cars. Dip motor in cup of water, run for a while, dry, clean and lube. It was the painless way to break in a motor.

2015.01.27, 12:55 PM
I used a very similar method when I was racing 1/12 scale cars. Dip motor in cup of water, run for a while, dry, clean and lube. It was the painless way to break in a motor.

Agreed, the submerged wear-in method is the best approach, as the water provides a mild abrasive property to the brush/commutator contact, which catalyzes the process of maximizing the contact surface area. Also, the brush material that gets worn off, washes away in the water instead of building inside the motor. The trick is knowing how long is long enough, to know when you've maximized performance.

If you apply a constant voltage to the motor when wearing in, monitor the current draw. As the surface area contact improves, the motor should draw more current. When this current levels off, you are done. Until this current levels off, you have more wearing in to do.