Target Audience:
Rec Sport and trail riders, from intermediate to experienced, as well as DIY owners performing their own service.
Market Segment:
Entry-to-mid-level performance ATV during its production run.
Primary Rivals:
Honda TRX300X / 300EX, Suzuki LT250R-era sport quads, Polaris Trail Blazer.
Key Advantage:
Proven air/oil-cooled 348cc single with a shaft-like simple chain final drive, robust chassis, and a long 15-year production run with strong parts availability.
Engine:
348cc air/oil-cooled SOHC single-cylinder four-stroke.
Suspension:
Independent double wishbone front with rear swingarm.
Brakes:
Dual hydraulic front disc brakes with rear disc.
Manual Type:
Factory-style service and repair manual
Coverage Areas:
Engine, fuel, cooling, chassis, suspension, brakes, drivetrain, electrical, and general maintenance.
Delivery Method:
Instant digital download
Compatibility:
Viewable on computers, tablets, and smartphones with a PDF reader.
Printing:
Printable pages for shop or garage use.
Engine:
Cylinder head, valves, camshaft, pistons, crankshaft, and oil cooling system service.
Fuel System:
Mikuni carburetor disassembly, jetting, tuning, throttle, and fuel tank procedures.
Lubrication:
Oil system, oil pump inspection, and oil cooler service.
Electrical:
Ignition (CDI), starting and charging systems, lighting, switches, and wiring diagrams.
Chassis / Suspension:
Front double wishbone A-arms, rear swingarm, shocks, and steering stem service.
Wheels and Tires:
Wheel inspection, tire removal and mounting, and axle bearings.
Brakes:
Front and rear hydraulic disc brake calipers, master cylinders, pads, and bleeding.
Drivetrain:
Clutch, 6-speed transmission, shift mechanism, and final drive chain.
Frame and Body:
Frame inspection, fenders, handlebars, and footpegs.
Maintenance:
Scheduled service tables, fluid changes, cable and chain adjustment, valve clearance checks.
Diagnostics:
Troubleshooting charts for no-start, poor running, and electrical faults.
Repair:
Step-by-step teardown and reassembly with special tool references.
Torque Specifications:
Complete fastener torque tables throughout each chapter.
Specifications:
Full factory service specifications and wear-limit tables.
Level:
Complete workshop-level detail suitable for professional technicians and experienced DIY owners.
Illustrations:
Exploded views, photos, and wiring schematics.
Part Numbers:
Factory part references included where applicable in procedures.
Fluids:
Recommended oil, brake fluid, and lubricant specifications.
File Format:
PDF (searchable, bookmarked, zoomable)
Compatibility:
Windows, macOS, Linux, iOS, and Android — any device with a PDF reader
Requirements:
A PDF reader application (e.g. Adobe Acrobat Reader, free)
Searchability:
Fully text searchable for fast lookup of any topic
Print Quality:
High-resolution digital pages, printable at full clarity
Binding Type:
N/A — digital download, no physical binding
Paper Type:
N/A — digital download, no physical paper
Engine Type:
348cc air/oil-cooled SOHC 4-stroke single cylinder
Bore x Stroke:
83mm x 64.5mm
Compression Ratio:
Approximately 9.2:1
Carburetor:
Mikuni constant-velocity (CV) type
Starting System:
Electric and recoil (kick) start
Ignition:
CDI (capacitor discharge ignition)
Fuel Capacity:
Approximately 2.4 gallons (9 liters)
Fuel Type:
Regular unleaded gasoline
Type:
6-speed constant-mesh manual transmission
Clutch:
Wet, multi-plate manual clutch
Final Drive:
Chain (O-ring or standard roller chain)
Shifting:
Foot-operated sequential shift lever
Wheelbase:
Approximately 47.2 inches (1,200 mm)
Overall Length:
Approximately 71.5 inches (1,815 mm)
Ground Clearance:
Approximately 5.3 inches (135 mm)
Seat Height:
Approximately 30.1 inches (765 mm)
Curb Weight:
Approximately 397 lbs (180 kg)
Fuel Tank Capacity:
Approximately 2.4 gallons (9 liters)
Crash Test Ratings:
N/A - ATVs are not assigned consumer crash test ratings.
Regulatory Compliance:
Meets ANSI/SVIA 1 ATV standards of its era; youth use subject to age guidelines.
Active and Passive Features
Brakes:
Dual front hydraulic disc brakes and rear hydraulic disc brake.
Lighting:
Headlight and taillight for visibility.
Engine Stop:
Engine stop (kill) switch on handlebar.
Owner Safety:
Helmet, eye protection, and protective gear strongly recommended per factory warnings.
Engine Oil:
Replace initially at 1 month (or as scheduled), then every 6 months or as usage dictates.
Oil Filter:
Replace with every other oil change per schedule.
Valve Clearance:
Check periodically per scheduled maintenance table (cold engine).
Air Filter:
Clean frequently, especially in dusty conditions; replace when deteriorated.
Spark Plug:
Inspect and adjust regularly; replace per interval.
Drive Chain:
Check and lubricate every ride interval; adjust slack to specification.
Brake Fluid:
Replace every 2 years; check level regularly.
Carburetor:
Inspect and synchronize idle per schedule.
Engine Oil:
SAE 10W-40 API SE (or higher) 4-stroke motor oil per factory spec.
Oil Capacity:
Approximately 2.6 liters (2.75 US qt) at oil change without filter removal; verify with dipstick.
Brake Fluid:
DOT 4 hydraulic brake fluid.
Final Drive Chain Lube:
Chain lubricant suitable for O-ring chains where fitted.
Known Issues / Common Wear Items
Common Wear:
Chain and sprockets, brake pads, air filter element, and clutch plates.
Known Issues:
Cam chain tensioner wear and carburetor gumming from stale fuel are frequently reported on stored units.
Manufacturer:
Yamaha Motor Company, a Japanese manufacturer of motorcycles, ATVs, and power products since 1955.
ATV Lineage:
Yamaha built its ATV reputation with the Tri-Z and early four-wheel Quads before the Warrior.
Introduction:
The Warrior 350 (YFM350X) was introduced in 1987 and continued largely unchanged through the 1990-2004 range covered here.
Discontinuation:
Production ended after 2004, succeeded in the lineup by the Raptor 350.
Production Location:
Japan
Production Run:
1987-2004 (15+ years), one of the longest-running sport ATVs of its era.
Market Standing:
Long regarded as a benchmark mid-size sport ATV of the 1990s, with a reputation for durability and a strong aftermarket following.
Longevity:
Over 15 years of continuous production with minimal changes - evidence of a mature, proven design.
Official Awards:
N/A - no widely documented formal awards for this specific model.
