Suzuki GSX400 Impulse (GK7CA) — OEM Fluid, Tire Pressure & Maintenance Specs
399cc Liquid-Cooled Inline-4 DOHC 16-Valve (Classic JDM Super-Four Rival) · Source: Suzuki GSX400 Impulse (GK7CA) (1994–2008) Official Owner’s Manual Maintenance Specifications
According to the Suzuki GSX400 Impulse (GK7CA) (1994–2008) Official Owner’s Manual Maintenance Specifications, the 1994–2008 Suzuki GSX400 Impulse (GK7CA) (chassis GK79A/GK7CA) requires 2.6 L (2.75 US qt) of SAE 10W-40 (JASO MA2, API SJ/SL/SM/SN) engine oil for a drain-only change and 2.9 L (3.06 US qt) with filter service (16510-07J00 / HF138 (M20×1.0 Fine Thread)). Standard solo cold tire pressure is 225 kPa / 2.25 bar / 33 PSI front (110/70-17 54H) and 250 kPa / 2.50 bar / 36 PSI rear (140/70-17 66H), paired with 4× NGK CR8E spark plug(s) and a YTZ10S / YTX12-BS battery.
Drain only: 2.6 L (2.75 US qt)
R 250 kPa (2.50 bar)
Est. Range: ~320 km (199 mi)
1. Engine Lubrication, Filter & Clutch Specifications
| Clutch Architecture | Wet Multi-Plate Manual Clutch NEVER use JASO MB |
|---|---|
| Recommended Viscosity & Grade | SAE 10W-40 (Alt: SAE 10W-50) · JASO MA2 · API SJ/SL/SM/SN |
| Oil Volume (Drain / With Filter / Overhaul) |
• Drain only: 2.6 L (2.75 US qt) • With filter/strainer: 2.9 L (3.06 US qt) • Complete dry overhaul: 3.3 L (3.49 US qt) |
| OEM Oil Filter Code & Type | 16510-07J00 / HF138 (M20×1.0 Fine Thread) |
| Correct Oil Level Check Method | Hold bike upright on level ground 3–5 min after warm shutdown; read crankcase sight glass |
| Oil Drain Bolt Torque | 23 N·m (17.0 lb-ft / 2.35 kgf·m) — Use fresh crush washer |
2. Cold Tire Pressures, Wheels, Ignition & Drivetrain
| Front / Rear OEM Tire Sizes | Front: 110/70-17 54H · Rear: 140/70-17 66H (Tubeless) |
|---|---|
| Cold Tire Pressure — Solo Riding |
Front: 225 kPa / 2.25 bar / 33 PSI Rear: 250 kPa / 2.50 bar / 36 PSI |
| Cold Tire Pressure — 2-Up / Loaded Touring |
Front: 225 kPa / 2.25 bar / 33 PSI Rear: 250 kPa / 2.50 bar / 36 PSI |
| OEM Spark Plug & Quantity | NGK CR8E × 4 (Gap: 0.8–0.9 mm) |
| OEM Battery Code & Rating | YTZ10S / YTX12-BS (12V 8.6–10Ah MF AGM) |
| Final Drive Maintenance | 525 Heavy-Duty Sealed X-Ring Chain — Maintain 25–35 mm slack and clean/lube regularly |
| Brake Fluid & Coolant | DOT 4 · Silicate-free ethylene-glycol OAT coolant for aluminum radiators (50:50 premix) |
3. Ergonomics, Range & Scheduled Service Intervals
| Displacement · Max Power · Peak Torque | 399 cc · 53 hp @ 11,000 rpm · 37 N·m (27.3 lb-ft) @ 9,500 rpm |
|---|---|
| Seat Height & Wet Curb Weight | 760 mm (29.9 in) · 197 kg (434 lbs) |
| Fuel Tank & Est. Real-World Range | 16 L (4.2 US gal) · ~20 km/L → ~320 km (199 mi) |
| OEM Scheduled Maintenance Intervals |
• First Break-In: 1,000 km • Engine Oil / Filter: 6,000 km / 18,000 km • Air Filter / Spark Plug: 18,000 km / 12,000 km • Valve Clearance Check: 24,000 km |
4. Generation Cutoffs & Real-World Wrenching Gotchas
Model-Year & Chassis Generation Notes
Suzuki’s liquid-cooled 400cc four rival to the CB400SF, celebrated in Yoshimura livery and revived in 2004–2008 (GK7CA) with Brembo front brakes.
Oil & Clutch Mechanical Engineering Note
Suzuki multi-cylinder family exclusively uses a proprietary M20×1.0 fine-thread spin-on filter (16510-07J00 / HF138)—never force an M20×1.5 filter onto the boss.