KYMCO Downtown ST 125i — OEM Fluid, Tire Pressure & Maintenance Specs
124.8cc Liquid-Cooled Single SOHC 4-Valve with Bosch 9.1M ABS · Source: KYMCO Downtown ST 125i (2015–Present) Official Owner’s Manual Maintenance Specifications
According to the KYMCO Downtown ST 125i (2015–Present) Official Owner’s Manual Maintenance Specifications, the 2015–Present KYMCO Downtown ST 125i (chassis SK25/V2-A0) requires 1.1 L (1.16 US qt) of SAE 10W-40 (JASO MB, API SJ/SL Synthetic 10W-40) engine oil for a drain-only change and 1.3 L (1.37 US qt) with filter service (1541A-LEA7-E00 / HF566). Standard solo cold tire pressure is 195 kPa / 1.95 bar / 28 PSI front (120/80-14 58S) and 220 kPa / 2.20 bar / 32 PSI rear (150/70-13 64S), paired with 1× NGK CR7E spark plug(s) and a YT12A-BS battery.
Drain only: 1.1 L (1.16 US qt)
R 220 kPa (2.20 bar)
Est. Range: ~413 km (257 mi)
1. Engine Lubrication, Filter & Clutch Specifications
| Clutch Architecture | Dry Centrifugal CVT Belt Drive |
|---|---|
| Recommended Viscosity & Grade | SAE 10W-40 (Alt: SAE 5W-50) · JASO MB · API SJ/SL Synthetic 10W-40 |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 1.1 L (1.16 US qt) • With filter/strainer: 1.3 L (1.37 US qt) • Complete dry overhaul: 1.5 L (1.59 US qt) |
| OEM Oil Filter Code & Type | 1541A-LEA7-E00 / HF566 |
| Correct Oil Level Check Method | Hold upright on level ground; rest dipstick UNTHREADED on filler neck (do NOT screw in) |
| Oil Drain Bolt Torque | 25 N·m (18.4 lb-ft / 2.55 kgf·m) — Use fresh crush washer |
| Final Drive / Bevel Gear Oil | 210 ml (0.21 L) — SAE 80W-90 / SAE 90 Hypoid Gear Oil (180–230 ml) |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 120/80-14 58S · Rear: 150/70-13 64S (Tubeless) |
|---|---|
| Cold Tire Pressure — Solo Riding |
Front: 195 kPa / 1.95 bar / 28 PSI Rear: 220 kPa / 2.20 bar / 32 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 200 kPa / 2.00 bar / 29 PSI Rear: 245 kPa / 2.45 bar / 36 PSI |
| OEM Spark Plug & Quantity | NGK CR7E × 1 (Gap: 0.7–0.8 mm) |
| OEM Battery Code & Rating | YT12A-BS (12V 10.0Ah MF AGM) |
| Final Drive Maintenance | Dry Centrifugal V-Belt CVT — Inspect/replace V-belt and rollers every 15,000–20,000 km |
| Brake Fluid & Coolant | DOT 4 · OAT ethylene-glycol coolant for aluminum radiators (50:50 premix) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 125 cc · 14.3 hp @ 9,000 rpm · 11.2 N·m (8.3 lb-ft) @ 7,000 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 775 mm (30.5 in) · 178 kg (392 lbs) |
| Fuel Tank & Est. Real-World Range | 12.5 L (3.3 US gal) · ~33 km/L → ~413 km (257 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 300 km • Engine Oil / Filter: 5,000 km / 5,000 km • Air Filter / Spark Plug: 10,000 km / 10,000 km • Valve Clearance Check: 15,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Sharing the full-size chassis, 120/150 tires, and twin-helmet storage of the 350i while running a high-output 14.3 hp liquid-cooled 125cc 4-valve single for A1 license riders.
Oil & Clutch Mechanical Engineering Note
Pulling a 178 kg maxi-scooter body keeps the 125cc single spinning near 8,000+ rpm—change full-synthetic SAE 10W-40 JASO MB oil (1.3 L w/ filter HF566) every 3,000–4,000 km.
Garage Wrenching Gotchas
- Heavy maxi-body mass accelerates variator roller flat-spotting and V-belt wear on a 125—inspect CVT rollers at 12,000–15,000 km rather than waiting for 20,000 km.
- Check oil level on the centerstand with the dipstick resting unthreaded on the neck; overfilling past MAX noticeably saps top-end speed on this high-RPM 125.
5. Frequently Asked Questions (FAQ)
What are the engine oil and rear hub gear oil capacities for the KYMCO Downtown ST 125i scooter?
With an isolated dry CVT belt case, the engine requires 1.1 L drain-only or 1.3 L (1.37 US qt) with filter/screen (1541A-LEA7-E00 / HF566) of SAE 10W-40 (JASO MB). Service the rear reduction hub separately (final drive 210 ml).
How do you accurately check the oil level on the Downtown ST 125i, and what are its service intervals?
Hold the bike upright on level ground 2–3 minutes after shutdown, wipe the dipstick, and rest it on the filler threads without screwing it in (threading it in reads artificially high and risks oil starvation). Torque the drain plug to 25 N·m with a new crush washer. Factory oil change intervals are every 5,000 km, with valve clearance inspection every 15,000 km.
What are the cold tire pressures, puncture repair type, seat height, and range of the Downtown ST 125i?
Fitted with 120/80-14 58S front and 150/70-13 64S rear tubeless rims (compatible with roadside plug kits), set cold tire pressures to 28 / 32 PSI (195/220 kPa) solo or 29 / 36 PSI loaded. Seat height is 775 mm (30.5 in) at 178 kg wet weight, delivering ~413 km per 12.5 L tank.