1987–1988 Yamaha Terra Pro YFP350 Service Manual (P/N LIT-11616-06–46)

This 435-page PDF contains Yamaha's factory YFP350U Service Manual, publication LIT-11616-06-46 with cover code 2NL-28197-10, first edition February 1987. It is specific to the YFP350U TerraPro, covering the 2NL configuration and the Canadian 2TX configuration. The manual identifies starting VINs JY42NLA0*JC000101 and JY42TXN0*JC000101 for Canada, together with engine starting numbers 2NL-000101 and 2TX-000101.

• Covers periodic inspection and adjustment for the engine, clutch, cooling-fan belt, front and rear brakes, parking brake, PTO clutch, governor controls, differential lock, drive-select system, steering, suspension, battery, and lighting.
• Details engine removal, internal disassembly, inspection, repair, reassembly, timing, and adjustment for the cylinder head, valve train, piston and cylinder, crankshaft, balancer gears, wet multi-disc clutch, oil pump, transmission, starter system, and PTO drive components.
• Includes carburetor sectional-view data and full service procedures for the Mikuni BTM32SH carburetor, mechanical governor, governor clutch, solenoid valve, and three-cable wire-cylinder assembly.
• Covers differential gear, constant-velocity joint, dual-range sub-transmission, and PTO gearbox removal, inspection, reassembly, installation, operational checks, gear-lash measurement, shim selection, and drive/driven gear positioning.
• Provides front mechanical drum-brake service and rear hydraulic drum-brake overhaul, including master-cylinder and wheel-cylinder inspection, seal replacement, reassembly, and brake-system bleeding.
• Includes YFP350U circuit diagrams and fault-isolation charts for CDI ignition, electric starting, charging, lighting, and signal systems, plus seat, clutch, PTO, governor, differential, 2-point-hitch, neutral, reverse, and high-range interlocks.
• Identifies Yamaha service tools by part number, including PTO ring-nut wrench YM-36626, PTO shaft holder YM-36625, gear-lash tool YM-01230, dial gauge YM-03097, crankcase separating tool YU-01135, and flywheel puller YM-01404.

Engine, Governor, and PTO Repair Coverage

The engine chapter distinguishes work that can be handled in the chassis from a complete engine pull. It states that the cylinder, flywheel magneto, and sub-transmission gears can be removed without taking the entire engine out, then documents full removal when bottom-end repair is required. The overhaul material proceeds through cooling fan and pulley, Canadian-market recoil starter, cylinder head and cylinder, piston, CDI rotor, cam chain, crankcase covers, PTO drive pulley and gear, clutch, balancer gears, oil pump, shifter, crankcase, transmission, and crankshaft. Inspection limits, bearing checks, valve-seat work, cam timing, assembly references, and component-specific torque data are tied to the relevant operations.

The carburetion section goes beyond ordinary carburetor cleaning. It maps the main-metering, starter, pilot, and float circuits; covers float and fuel-level adjustment; and treats the governor as a separate repairable assembly with flyweights, sleeve, fork, link rod, butterfly valve, solenoid valve, clutch shaft, lifter, and control cables. The manual also documents governor-speed adjustment, governor-clutch cable setup, control-lever holding-cable adjustment, and governor oil service. For the Canadian 2TX configuration, it adds dedicated recoil-starter disassembly, inspection, and assembly coverage.

Drivetrain, Chassis, and Electrical Diagnosis

The dual-range drive system receives its own troubleshooting and overhaul chapter. Noise, leakage, bearing condition, gear-tooth damage, and incorrect gear lash are used to narrow faults before the differential, CV joint, rear axle, sub-transmission, or PTO gearbox is opened. The PTO section includes the factory measurement method with the specified holder, ring-nut wrench, dial gauge, and gear-lash fixture, followed by shim selection and gear-position calculations when the case or drive components are replaced.

Chassis repair extends from wheel bearings and brake drums through steering shaft, tie-rods, steering knuckles, lower arms, front struts, rear shocks, swingarm, rear axle, and differential housing. The rear brake is a hydraulic drum system, so the manual includes brake-pipe and hose service, master- and wheel-cylinder repair, fluid requirements, seal replacement rules, and air bleeding.

Electrical diagnosis is organized around system-specific circuit diagrams and decision charts. Tests cover ignition spark and coil/source-pickup circuits, CDI and governor inputs, starter motor and cut-off relays, magneto output and regulation, headlight and taillight supply, and the neutral, reverse, temperature, parking-brake, and PTO indicator circuits. The engine-operation-pattern charts show how the seat, PTO, 2-point hitch, clutch, transmission position, speedometer reed switch, and governor circuits control starting, stalling, and ground-speed limiting.

Reference Data, Diagrams, and Repair-Critical Details

Factory data includes model identification, maintenance specifications, tightening-torque tables, lubricant types and capacities, cable adjustments, wear limits, clearances, carburetor settings, PTO gear-lash data, and electrical test values. Diagram coverage includes the engine lubrication layout, PTO drive-axle lubrication view, carburetor sectional view, governor and PTO exploded assemblies, multi-page cable-routing layouts, CDI internal circuit diagram, system circuit diagrams, and the full YFP350U wiring diagram.

Several cautions are specific to this machine. PTO gear setup depends on correct shim placement and controlled bearing-housing tightening; too little lash can quickly damage the gear teeth. The governor clutch must be indexed correctly at the lifter and case match marks or the clutch shaft may not turn. Rear-brake parts must be cleaned with fresh brake fluid only, since excess grease, sealant, dirt, or solvent can damage seals, block fluid passages, contaminate the linings, and reduce braking performance.

Use secure supports for drivetrain and suspension work, isolate battery power before electrical testing, and keep clear of the cooling-fan and PTO belts during running checks. Any opened rear-brake hydraulic circuit must be restored and bled before the machine is returned to service.

This description summarizes the publication's coverage and does not reproduce its repair instructions.