1970s–1980s Honda BF75 & BF100 Outboard Motor Shop Manual with BF8A Supplement (P/N 6688122)

This Honda shop manual, Publication No. 6688122, covers 1970s–1980s BF75 and BF100 outboard motors in Short and Long shaft configurations, with service procedures for serial numbers 1000004 and subsequent. BF75/BF100 Supplement 6688120Z and BF8A Supplement 6688121Z are included.

Supplied as a single English-language, 119-page PDF, including the supplements, service bulletin, and index detailed below.

• Engine repair: Engine and lower-unit removal, cylinder-head disassembly, valve-seat refacing, valve-clearance adjustment, camshaft and piston inspection, oil-pump service, and timing-belt installation.

• Fuel and cooling: Carburetor disassembly and adjustment, diaphragm fuel-pump inspection, thermostat testing, cooling-water tube routing, and water-pump impeller service.

• Electrical diagnosis: Contact-breaker and CDI wiring diagrams, coil and rectifier tests, neutral-switch checks, ignition timing adjustment, and DC output diagnosis.

• Gear case and controls: Propeller-shaft and bevel-gear service, shim and washer selection, shift-rod adjustment, and throttle-cable setup.

• Starting and mounting: Recoil starter repair, swivel-case and stern-bracket disassembly, reverse-lock service, and optional remote-control bracket installation.

• Workshop references: Dimensional drawings, disassembly and lubrication charts, maintenance schedules, troubleshooting charts, torque specifications, wear limits, and special-tool listings.

Suited to mechanics comfortable with engine disassembly and precision measurement; CDI diagnosis also requires the specified electrical test equipment.

Engine Inspection and Repair

"Standard vs. Service Limit" tables cover the valve train, pistons, cylinders, crankshaft bearings, and oil pump. Cam-height specifications distinguish the two models and their CDI or contact-breaker configurations. These comparisons help technicians assess measured wear before replacing original parts.

Exploded-view assemblies document component placement, lubrication points, and reassembly details. Cylinder-head work extends to valve-guide replacement and valve-seat refacing; routine maintenance includes spark-plug cleaning and adjustment.

The compression-test instructions flag possible ignition-coil damage from cranking with the spark plugs removed without the specified electrical precautions.

Fuel Delivery and Cooling

Separate fuel-pump assemblies apply through BF75 1102880/BF100 1101260 and from BF75 1102881/BF100 1101261 onward. Carburetor coverage includes float-level inspection, main-jet and nozzle service, and linkage adjustment.

The Cooling System illustration traces water circulation through the impeller pump, bypass tubing, thermostat, and engine jackets. Thermostat specifications distinguish production changes, including the low-temperature version identified for Canadian Long-shaft models.

Ignition, Charging, and Starting Faults

CDI wiring layouts distinguish engines at 1200001–1299999 from 1300001 onward, including the neutral-start interlock. Later CDI resistance tables have separate model breakpoints at BF75 1300701 and BF100 1300703.

Honda specifies SANWA tester 07308-0020000 or the listed KOWA alternatives for CDI testing; an unsuitable tester or range can give false readings. Component checks cover primary, exciter, charging, ignition, and pulser coils, plus the oil-pressure warning circuit and stop switch.

The Hard Starting flowchart connects fuel-delivery, spark, and compression checks with probable causes. Contact Breaker Type and C.D.I. Type schematics include component-code and wire-color keys.

Lower-Unit Repair and Remote Controls

Lower-unit repair extends to the propeller shaft's clutch shifter and spring, bearings, water seals, and bevel gears. The Shim and Washer Selection section matches gear-case markings to the required shims and thrust washers; Power Flow diagrams explain forward, neutral, and reverse operation.

Remote-control bracket installation includes cable selection and hook-up at the outboard. Its adjustment warning explains how throttle movement before gear engagement can strip the gears.

Production Updates and BF8A Coverage

BF75/BF100, serial 1700001 onward: The supplement documents revised tube routing, fuel-strainer replacement, thermostat checks, exhaust-pipe cooling, and anode placement.

BF8A: The supplement identifies S/L configurations as BACS/BACL and compares camshaft, valve-clearance, carburetor, impeller-pump cover, and reverse-lock changes. BF8A-specific repair coverage concentrates on the reverse lock and swivel case, with other procedures relying on the base manual.

Shop Manual News P/P-005: This bulletin separates frame serial numbers 1000001–1099999 from 1100001 onward and documents fuel-connection, shift-rod, DC connector, emergency-stop-switch, and wiring changes.

Handle fuel-system components with care, ensure proper workshop ventilation, and consult a qualified marine technician for work beyond your experience.

File Contents and Readability

The 119-page total comprises:

• Main manual: 102 pages.
• BF75/BF100 supplement: 9 pages.
• BF8A supplement: 5 pages.
• Shop Manual News: 2 pages.
• Final page-range index: 1 page.

Cover, preface, and contents pages are already included in these counts.

Text search: Only the final index page has searchable text; the technical manual pages do not.

Navigation: Embedded bookmarks cover the main chapters and supplements. The Frame part bookmark lands one page before that section.

Wiring readability: Main wiring diagrams are readable with zooming. Some small labels in the bulletin on PDF page 118 remain difficult to read when enlarged.