2007 Yamaha F350 & LF350 Outboard Motor Factory Service & Repair Manual (P/N LIT-18616-03-02)

Yamaha’s 2007 F350 and LF350 service manual, publication LIT-18616-03-02, first edition July 2007, covers maintenance, diagnosis, and repair of the 6AW/6AX outboards, including regular- and counter-rotation models.

• Power unit: Removal and installation, cylinder-head and crankcase disassembly, valve-guide replacement, valve-seat refacing, timing-belt replacement, and valve-clearance adjustment.

• Fuel system: Fuel-pressure and regulator tests, vapor-separator servicing, low-pressure pump disassembly, injector checks, and fuel-rail installation.

• Electronic diagnosis: YDIS troubleshooting, ECM and sensor circuit checks, ignition and charging tests, starter-motor overhaul, and Digital Electronic Control fault tracing.

• Lower unit: Separate regular- and counter-rotation procedures for gears, bearings, propeller shafts, water pumps, backlash measurement, and shim selection.

• Bracket and PTT: Steering-arm and bracket service, hydraulic-pressure checks, pump and cylinder disassembly, motor inspection, and bleeding off the motor or installed.

• Rigging and maintenance: Single- and twin-engine installation, battery wiring, network connections, tilt-limiter setup, predelivery checks, and periodic service schedules.

Written primarily for Yamaha dealers and trained mechanics, this manual assumes YTA Marine Bronze-level knowledge or an equivalent understanding of the mechanical and electrical principles involved.

Powerhead Repair and Timing

The workshop documentation includes piston, camshaft, and valve inspection criteria, crankpin and main-bearing selection tables, and factory tightening sequences. Power-unit removal specifies engine lifting eye 90890-06820 and balance hanger 90890-06822.

Timing coverage includes Variable Camshaft Timing, oil-control valves, belt alignment, and flywheel installation with new bolts. The procedures warn about piston/valve damage from incorrect crankshaft or sprocket rotation, and impeller damage from counterclockwise flywheel rotation during inspection.

Fuel Delivery and Cooling

Fuel-system coverage follows the pressure regulator, fuel cooler, vapor separator, and canister/vapor shut-off circuit, with fuel, vapor, and cooling-hose routing views.

Thermostat testing and cooling-passage checks accompany the explanation of water-wall cooling around the muffler.

Follow the manual’s pressure-release precautions for fuel-line and vapor-separator service. Use its specified lifting provisions when handling heavy engine assemblies.

YDIS and Control-System Fault Tracing

The diagnostic chapters connect trouble codes and symptoms to specific circuit checks, including faults that do not set a code. This helps distinguish wiring or sensor problems from mechanical causes before selecting the next test.

The manual explains electronic fuel injection control, ignition-timing strategies, and ion-knock detection through the Ionic Current Detection Module. ECM coupler layouts, circuit diagrams, and the foldout color wiring diagram support connector and harness tracing.

YDIS functions include stationary/active tests, recorded-data review, Digital Electronic Control reset, and tilt-limiter setup. These procedures call for YDIS 1.30 or later and the dedicated connection kit, identified as 60V-85300-04-00.

Gearcase, Bracket, and Rigging Work

Regular- and counter-rotation lower units have different gear/shim assignments; the LF350 section also covers propeller-shaft shim T4. The appended pinion-calculation and shim-adjustment tables distinguish the two configurations.

PTT hydraulic diagrams explain ram operation, while repair sections cover the gear pump, relief valves, and trim/tilt cylinders. Bracket coverage extends to the upper case, steering arm, clamp bracket, and swivel bracket.

Digital network diagrams distinguish single- and twin-engine installations. Battery diagrams cover arrangements with and without a house battery; Command Link gauge installation is referred to a separate setup manual.

A Preview of Engine Clearances and Fuel-Pressure Data

For F350 and LF350 cylinder-head inspection, the warpage limit is 0.08 mm. Intake valve clearance is 0.20 ± 0.03 mm with the engine cold.

Crankshaft journal oil clearance is position-specific: 0.026–0.051 mm at J1/J3, 0.038–0.063 mm at J2/J4, and 0.032–0.057 mm at J5. The overhaul section pairs these checks with main-bearing selection tables.

Fuel-pressure diagnosis lists 260 kPa as reference data with the engine warmed up at stable idle.

Searchable PDF and Foldout Wiring Reference

Search, bookmarks, and diagram detail: The manual text is searchable, with embedded chapter and section bookmarks. Small wiring labels and connector numbers require zooming, especially in the wide color wiring diagram.

Supplied as one printable PDF in English with 549 pages, including the cover, front matter, four blank pages, and four memo pages. The total also includes the appended color wiring diagram and six pages of lower-unit shim-selection tables.