View Full Version : How do I remove the pot to clean it? MR-03S2

2016.01.27, 11:00 AM
So my steering on my MR-03S2 has started to glitch out when I turn right. It's stuttering and jittering. I read that it is probably a dirty or bad pot?

I looked at my manual for the exploded views and tried to find some info online but I just can't figure out how to get this pot out. It so wedged in and tight in there still. I don't see any other place to loosen anything. I bought some di-electric grease to put on after cleaning. I just can't get it out. :(

This is what I'm looking at. Any help would be very appreciated. Thanks!


2016.01.27, 11:07 AM
Remove the bottom cover and you should be able to push out the gear box....I can't recall if pops.out to the top or bottom.

From there you should be able to remove the front plate of the gear box and access the pot.

2016.01.27, 11:11 AM
I would sooner do a radio reset before I would clean the pot. Unless you opened it up and there was just mounds of dirt and dust in there, then yeah... spray it out. But even then... I wouldn't drown the pot in cleaner. If you do spray it, try to use something like RC electric motor spray... something that dries without residue.

KT19 reset post...


I used to obsess about glitch in the AM days... ever since 2.4, I haven't really dealt with pots much at all!

And as far as getting that assembly out of an 03, I'm pretty sure it slides out the bottom of the chassis. I know I had to take off the top and bottom to get mine out.

2016.01.27, 11:43 AM
The series 2 of the sport edition requires the tx reset as well?

I had read the a lot of the electronics issues of the original sport edition were fixed with the 2nd series. Guess not that one?

I did not buy any cleaner, just the lube to apply after. I had read to use some rubbing alcohol and a q-tip or something small like that.

The steering works fine to the left. When I turn it to the right, the wheels keep jumping and stuttering constantly. All the things I read pointed to a dirty/busted pot.

If I don't have to take it out, all the better.

So those larger screws on the underside need to come out as well then if that plate needs to be removed. After that, I should be able to slide the whole gear housing down out of the bottom?

Is it possible to spray/clean the tap from its housed position?

2016.01.27, 12:01 PM
I have never cleaned the pot on any of my cars, some I have been running for 3 years or longer. I have cleaned out the gears. they always seemed to be a little jittery when sitting but not when driving.

2016.01.27, 12:39 PM
here is the exploded view (http://www.kyosho.com/jpn/support/instructionmanual/mini-z/pdf/MR03S2-T02_ex.pdf)

the assembly slides out the top. you then pull out the servo motor out of the assembly and its free except the 3 wires to the POT. be careful, the wires to the servo motor break easily. reverse order to get it in, inset the servo motor into the assembly and slide assembly into chassis.

this all assumes you don't loose the two very tiny screws holding the servo motor in place. :rolleyes:

2016.01.27, 03:43 PM
I have that same exploded view in the manual. I just couldn't tell which direction they parts go in/come out. That view only helps if you already have the gears taken out of the car, which is my initial problem.

Would the gears cause the wheels to look like they are having seizures when I turn in one direction? They are jittering back and forth but only when I turn it to the right. Might be left but it's only when going in the one direction.

I could try to blow some air down into the gears. This is the first thing on my mini-z to go wrong so far. Just seemed like a bitch to get in there and clean it.

I'll see if just blowing it out does the trick before I try to take out the servo/gears.

2016.01.27, 04:57 PM
You need to remove the servo motor screws and pull the motor out of the end of the servo gear pod. The servo motor kinda holds that from sliding up or down. Pulls out of the top of the car when that is removed. The servo pot wires are not long enough to pull it out through the bottom of the car.

2016.01.27, 05:51 PM
You might want to check the gear teeth of the fourth gear (the furthest from the motor in the gear box) the teeth might be stripped for the right side turn.

2016.01.27, 05:54 PM
How would they get stripped inside there? Is that common?

I can't find any videos of youtube on this which seems odd.

2016.01.27, 06:00 PM
It's not impossible. Kyosho makes an aluminum servo gear replacement for the one that is most susceptible. Just remember to take a picture for reference, helps when you want to get it all back together. Don't loose the spacer either. Difficult to replace if lost.

2016.01.28, 11:31 AM
I agree, sounds like a chipped tooth on the 4th.

Or, could "factory" center on the radio need to be reset? I never touched a Series 2 so I have no idea. To me though, it would still seem like the same radio. I only suggest this because after repairing rentals, a few of the cars had similar issues until I reset the radios. I don't know how the system "decides" where center is but apparently, it is not a constant.

Mike Keely
2016.01.28, 08:49 PM
I would put my money on the fourth gear also.

2016.01.29, 12:14 AM
Looks like the old Nintendo trick worked. I blew inside the gearbox a bunch and turned it on. The steering improved but I still saw a slight twitch. Blew in there for a bit more and tried again. Steering appears to be fixed. Drove it around my track for 2 battery rotations and no issues. I'm glad I didn't have to mess with that gearbox! (knock wood) I did buy di-electric grease but never used it since I didn't get to the pot.

I didn't mess with the radio or do any of the resetting either, whew! I also didn't see any issues with any of the gears. Might just be the lighting and all the black parts in the photo?

Hopefully she keeps holding together! ;) Thanks for all the help and recommendations!

2016.01.29, 05:45 AM
It's interesting that even though you can't see the dust, it's there.

Like others I don't do much servo maintenance. I wonder if this is more common with the Sports Series chassis.

Good to see everyone pitching in to help.