1990 Honda BF35A/BF45A & BF40A/BF50A Outboard Service Manual Set (P/N 66ZV300)

The 1990 Honda BF35A/BF45A shop manual, P/N 66ZV300, is supplied with five supplements and service-news bulletins. The base publication covers construction, operation, maintenance, and repair, with illustrations based primarily on the BF45A LRT.

• Engine repair: Powerhead removal and installation, cylinder-head service, valve-guide replacement, valve-seat reconditioning, crankshaft inspection, bearing selection, and oil-pump service.

• Fuel system: Carburetor disassembly, vacuum synchronization, dashpot adjustment, fuel-pump and strainer service, choke linkage, and remote choke solenoid inspection.

• Lower unit: Propeller-shaft service, water-pump repair, vertical-shaft and bevel-gear inspection, shim selection, and forward/reverse gear backlash adjustment.

• Tilt systems: Gas-assisted damper replacement, power trim/tilt troubleshooting, motor and hydraulic component service, air bleeding, and blow-pressure inspection.

• Electrical diagnosis: Starter-motor overhaul, CDI testing, ignition and charging-coil checks, regulator/rectifier inspection, alert-system fault charts, and wiring diagrams.

• Steering and controls: Steering rod, remote control box, throttle and shift cables, swivel case, stern bracket, and supplementary long-tiller-handle procedures.

Suited to mechanics familiar with outboard disassembly and the use of vacuum gauges, electrical testers, and bearing-service tools.

Base Manual and Supplement Coverage

The base manual contains seventeen sections. The BF40A/BF50A publications provide change-specific supplementary coverage, including later fuel, ignition, tiller, and tilt systems.

These supplements retain references to earlier publications 66ZV300Z and 66ZV300W, which are not included in this file. The individual supplements cover changed sections and rely on the base manual for shared procedures.

Powerhead, Timing Belt, and Cooling

Internal engine coverage includes crankcase separation, piston and ring inspection, camshaft measurements, and color-code bearing selection. Cylinder-head and crankcase assembly information distinguishes initial tightening from the additional angle stage.

Timing-belt sections document alignment marks, tensioner adjustment, and the warning against clockwise pulser-rotor rotation. Tool references include ring gear holder 07LPB-ZV30100 and lock nut wrench 07LPA-ZV30200.

Water-jacket, thermostat, and thermo-switch sections include removal, inspection, and operating-temperature checks.

Carburetors, Choke, and Starting Enrichment

The base carburetor procedures cover float inspection, pilot adjustment, synchronization, and acceleration/deceleration linkage. Later supplements add SE thermal-valve inspection and separate fuel, vent, vacuum, and enrichment tube-routing views.

The carburetor bulletin distinguishes engine-serial-specific pilot settings and Canadian limiter-cap arrangements. Removing a limiter cap is described as destructive replacement work, rather than a routine cleaning step.

Gear Case, Mounts, and Steering

Gear-case repair includes bearing removal, shim-selection tables, shim-position drawings, and backlash measurement. Supplementary change charts identify builds where reverse-gear shims were deleted, helping match the repair information to the gear-case version.

Primary gear case, oil pan, mount frame, and swivel-case procedures accompany the steering and control chapters. The primary gear case section explains how incorrect seal-rubber orientation allows water into the case. Long-tiller coverage extends to the shift unit, throttle grip, steering bracket, and friction adjustment.

Ignition Tests and Electrical Drawings

Resistance tables cover charging, exciter, pulser, and ignition coils alongside component locations and connector views. Engine, starter, ignition, and alert-system troubleshooting charts address different fault conditions.

The supplements distinguish analog CDI/exciter-coil arrangements from later digital CDI, power-coil, and ECT-sensor systems, helping select the matching diagnostic information before replacing ignition parts.

Drawing examples include remote-control/power-trim wiring, long-tiller/gas-assisted wiring, CDI connector views, and cable/harness routing.

Power Trim/Tilt Repair and Gas Damper Limits

The tilt supplements add motor inspection, valve-body and cylinder service, hydraulic air bleeding, and upper/lower chamber blow-pressure testing. Hydraulic tilt-up and tilt-down diagrams explain the related oil circuits.

Gas-assisted damper coverage includes removal and replacement; the drilling and pressure-release instructions concern disposal, not internal damper repair. A service bulletin also explains how motor-cord strain can deform the outlet grommet and allow water into the tilt motor.

Fuel-system work requires ventilation and ignition-source control. Running tests and pressurized tilt work require the manual’s applicable safety precautions.

Examples of Cooling and Engine Adjustment Data

These values are a small selection of the cooling and adjustment specifications in the base manual.

For the BF35A/BF45A, thermostat inspection lists 52°C (126°F) as the temperature at which opening begins.

Carburetor data specifies an idle speed of 950 ± 50 rpm at no load with the shift lever in neutral. Intake valve clearance is 0.13–0.17 mm with the engine cold.

PDF Search, Bookmarks, and Included Publications

Search and diagram detail: Text search is available on some later supplement pages; the base manual is not searchable. Embedded chapter and supplement bookmarks provide navigation. Small wiring labels require zooming. Some part-number and serial-number fields in the two September 2000 service-news bulletins are faint or unreadable.

One printable English PDF download contains 431 pages total, divided as follows:

The six service-news pages and the additional one-page index are already included in the total.