KYMCO Downtown ST 350i / 350i TCS — OEM Fluid, Tire Pressure & Maintenance Specs
320.6cc Liquid-Cooled Single SOHC 4-Valve G5-SC with Bosch ABS & TCS · Source: KYMCO Downtown ST 350i / 350i TCS (2015–Present) Official Owner’s Manual Maintenance Specifications
According to the KYMCO Downtown ST 350i / 350i TCS (2015–Present) Official Owner’s Manual Maintenance Specifications, the 2015–Present KYMCO Downtown ST 350i / 350i TCS (chassis SK64/C7-A0) requires 1.3 L (1.37 US qt) of SAE 10W-40 (JASO MB, API SJ/SL Synthetic 10W-40) engine oil for a drain-only change and 1.5 L (1.59 US qt) with filter service (1541A-LEA7-E00 / HF566). Standard solo cold tire pressure is 200 kPa / 2.00 bar / 29 PSI front (120/80-14 58S) and 225 kPa / 2.25 bar / 33 PSI rear (150/70-13 64S), paired with 1× NGK CR7E spark plug(s) and a YT12A-BS battery.
Drain only: 1.3 L (1.37 US qt)
R 225 kPa (2.25 bar)
Est. Range: ~331 km (206 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: 1.3 L (1.37 US qt) • With filter/strainer: 1.5 L (1.59 US qt) • Complete dry overhaul: 1.7 L (1.80 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 | 230 ml (0.23 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: 200 kPa / 2.00 bar / 29 PSI Rear: 225 kPa / 2.25 bar / 33 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 200 kPa / 2.00 bar / 29 PSI Rear: 250 kPa / 2.50 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 | 321 cc · 28.8 hp @ 7,500 rpm · 30 N·m (22.1 lb-ft) @ 5,750 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 775 mm (30.5 in) · 189 kg (417 lbs) |
| Fuel Tank & Est. Real-World Range | 12.5 L (3.3 US gal) · ~26.5 km/L → ~331 km (206 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
Succeeding the original Downtown 300i with a 320.6cc G5-SC motor and full-face 2-helmet underseat bay, gaining switchable TCS traction control and Euro 5 refinement from 2020+.
Oil & Clutch Mechanical Engineering Note
Built around KYMCO’s low-friction roller-rocker G5-SC head and dry CVT, taking 1.5 L of SAE 10W-40 JASO MB oil (with filter HF566) plus 230 ml of SAE 80W-90 rear gear oil.
Garage Wrenching Gotchas
- The YT12A-BS battery sits conveniently at the front of the underseat tub, but learn the mechanical key-turn seat latch detent in case winter parasitic draw drains the battery.
- Reset the dashboard OIL SERVICE indicator via the ADJ and MODE button sequence after every 5,000 km oil and HF566 filter service.
5. Frequently Asked Questions (FAQ)
What are the engine oil and rear hub gear oil capacities for the KYMCO Downtown ST 350i / 350i TCS scooter?
With an isolated dry CVT belt case, the engine requires 1.3 L drain-only or 1.5 L (1.59 US qt) with filter/screen (1541A-LEA7-E00 / HF566) of SAE 10W-40 (JASO MB). Service the rear reduction hub separately (final drive 230 ml).
How do you accurately check the oil level on the Downtown ST 350i / 350i TCS, 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 350i / 350i TCS?
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 29 / 33 PSI (200/225 kPa) solo or 29 / 36 PSI loaded. Seat height is 775 mm (30.5 in) at 189 kg wet weight, delivering ~331 km per 12.5 L tank.