"Mini-Z" is the common shorthand for 1/28-scale on-road racing. Almost everything here applies across 1/28 on-road cars, not just Kyosho's Mini-Z — and the same motors turn up in 1/28 drift, which runs its own classes.
The motor is the part new 1/28 racers reach for first — and the one they should usually upgrade last. The factory motor in a Mini-Z is faster than most beginners can use, and on the tight, low-grip indoor tracks these cars run, more power is often slower: it just spins the tires. Kyosho literally created its slowest brushless motor because customers asked for one. Before you spend on a motor, fresh tires and the right pinion do more for your lap times.
Where the motor does matter is matching it to your class rules and your track. This guide covers the two questions that confuse people most: brushed vs brushless, and what "stock" actually means — which, it turns out, is a different motor at almost every club.
Motor types at a glance
| Type | Rated in | What it means | Best for |
|---|---|---|---|
| Stock brushed (kit motor) | Turns (T) | More turns = more torque, lower RPM. The included motor. | Learning, box-stock classes |
| Upgrade brushed (Kyosho X-Speed, PN turn motors) | Turns (T) | Fewer turns = faster and hotter. ~70T is a common stock-legal motor; 30-40T is modified. | First upgrade, spec-brushed classes |
| Brushless, low KV (~3500-4100KV) | KV (rpm/volt) | Smooth, controllable, runs cool, lasts. The sweet spot for most tracks. | Most club racing, small tracks |
| Brushless, mid KV (~5000-5600KV) | KV | A handful unless you are experienced. | Larger tracks, advanced |
| Brushless, high KV (8500KV and up) | KV | Open/modified only — too fast for small layouts. | Big tracks, open class |
The key idea: brushed motors are rated in turns (lower = faster), brushless in KV (higher = faster). They are two different scales — you can't directly compare a "70T" to a "3500KV".
Brushed vs brushless — which should you run?
Brushless is the established upgrade: crisper throttle, smoother power, it runs cooler and lasts far longer than a brushed can. But two things trip people up:
- It's a system change, not a part swap. Brushless needs a brushless-capable board/ESC — Kyosho's EVO/VE chassis, or an aftermarket ESC from PN Racing or Atomic. You can't drop a brushless can into a brushed-only board.
- Pick low KV. 8500KV is unusable on a two-lane garage track; around 3500-4100KV is the comfortable range for most layouts. If a car is undriveably fast, the answer is usually less motor, not more.
The Kyosho brushless color ladder
Kyosho's brushless motors are color-coded by speed — the question people ask most. From slowest to fastest:
| Color | Relative speed | Typical use |
|---|---|---|
| Green | Slowest | Beginner / spec "stock" classes, small tracks |
| Blue | Medium | Popular all-round standard |
| Red | Fast | Faster / touring classes |
| Top tier | Fastest | Open / modified only |
We've left exact KV figures off the ladder on purpose: Kyosho has revised the KV ratings behind these colors across seasons, so the number printed on a current can is what counts. The order — green, blue, red, top — is what stays constant.
What "stock" really means (and why it's confusing)
There is no single "stock motor." What's legal depends entirely on where you race:
- Kyosho Mini-Z Cup (the main Japanese/official series): a mandated color motor (green/blue/red) with its RPM electronically capped, plus a limited pinion. "Stock" here is as much an electronic speed cap as a physical can.
- Club and PN World Cup stock: often the PN Racing 70-turn brushed motor (cheap), or a spec brushless like PN's 3500KV "PNWC Stock".
- Local clubs: brushless classes are usually KV-capped and tech-checked on a KV meter — for example a 2800KV ceiling for a LiPo-stock class — with aftermarket rotors banned.
Bottom line: check your club's rules before you buy a motor. The single most common beginner mistake is buying a motor that's illegal — or just pointless — for the class they'll actually run. (These numbers are examples; your club's will differ.)
Turns, KV, and how motor choice changes your gearing
Motor and pinion work together. Fewer winds (brushed) or higher KV (brushless) means more RPM and less torque; more winds or lower KV means more torque and less RPM. Match the pinion to the motor:
- Torquey motor (high-wind brushed / low-KV brushless) → pair with a larger pinion to put that torque to use.
- High-RPM motor (low-wind brushed / high-KV brushless) → pair with a smaller pinion, which lets you use the revs without overheating the motor or the board.
If a brushless car is too fast to drive, lower the gearing or drop to a lower-KV motor — don't reach for more power.
Maintenance and "is my motor dead?"
Brushed motors are a consumable — burning one out over time is normal, not a defect. Signs of a dying brushed motor: noticeably slower than it used to be, a hot "burnt-electrical" smell, an odd noise, or visible smoke. Blow the dust out with canned air now and then, and replace it when performance drops off. Brushless motors last far longer and need very little of this.
One catch that fools people: if the car runs fine off the track but bogs down under load, check for body or tire drag and a loose motor wire before blaming the motor.
Break-in is debated. Some racers do a brief, gentle low-voltage seat-in; others say modern motors don't need it, and water break-in in particular is best avoided on these small cans. There's no firm consensus, so don't feel you're missing a step by skipping it.
One motor, different platforms
The same small can motors are used across rear-drive (MR-03) and all-wheel-drive (MA-020/030) Mini-Z — Kyosho's brushless motors even appear in both RWD and AWD race classes. What changes between platforms is the pinion and the drivetrain the motor drives (AWD spins a central driveshaft front and rear; RWD drives the rear pod only), not the motor can itself. Just buy the motor your chassis and class call for.
Where to get one
For the Kyosho factory path, the XSpeed brushless line is the easy choice — pick the color for your class and track:
- Kyosho XSpeed 41 (green, controllable) at AMain
- Kyosho XSpeed 56 (blue, all-round) at AMain
- Kyosho XSpeed 85 (red, fast) at AMain
For spec and stock classes, PN Racing (the 70-turn brushed and the 3500KV "PNWC Stock" brushless), Atomic, and ReFlex Racing are the names to know — most easily found through Mini-Z specialist shops.
Related Mini-Z guides: MR-03 vs MR-04 and how to upgrade · tires by track surface.
