Brands: Onan / McGraw-Edison / Sperry New Holland / New Holland Agriculture
Equipment Type: Gasoline Engine
Manuals Type: Service Manual
Machine Model & Serial Number: B43E (Spec A), B43G (Spec A-C), B48G (Spec A-E)
Region: N/R
Book Code: 40545000 (965-0757)
Issued: July 1983
Language: English
Pages: 36
File Format: Portable Document Format (PDF)
Remark: Comprehensive factory engine service manual for Onan B-series engines. Extremely valuable: Features complete internal engine overhaul procedures including detailed specifications for cylinder reboring, piston ring gap, and crankshaft end play. Provides deep-level servicing data for Walbro and Nikki carburetors, mechanical governors, and battery ignition systems. Includes exhaustive assembly torque values and troubleshooting guides.
Table of contents
- GENERAL INFORMATION
- Introduction and Identification
- Engine Model Reference and Interpretation of Spec Numbers
- SPECIFICATIONS
- Bore, Stroke, Displacement, and Compression Ratios
- Rated Power and Oil Capacities
- Valve Clearances and Ignition Timing
- DIMENSIONS AND CLEARANCES
- Camshaft and Crankshaft Journal Limits
- Piston and Cylinder Clearance Specifications
- Valve Seat Width and Angle Data
- ASSEMBLY TORQUES AND SPECIAL TOOLS
- Cylinder Head, Connecting Rod, and Flywheel Torques
- Onan Specified Special Service Tools List
- ENGINE TROUBLESHOOTING GUIDE
- OIL SYSTEM
- Crankcase Oil and Filter Change Procedures
- Crankcase Breather Maintenance
- Oil Pump Assembly and By-Pass Valve Testing
- FUEL SYSTEM
- Walbro Carburetor Mixture Adjustments and Overhaul
- Nikki Carburetor Mixture Adjustments and Overhaul
- Pulsating-Diaphragm Fuel Pump Repair
- Air Cleaner Maintenance and Assembly
- Variable Speed Governor Sensitivity Setup
- IGNITION AND BATTERY CHARGING
- Breaker Point Adjustment and Timing (16°/20° BTC)
- Ignition Coil and Battery Testing
- Flywheel Alternator System (15 and 20 Amp)
- STARTING SYSTEM
- Electric Starter Disassembly and Overhaul
- Armature Testing for Grounds and Shorts
- Starter Gear Lash Adjustment
- ENGINE DISASSEMBLY AND ASSEMBLY
- Suggested Disassembly Order
- Valve System Reconditioning (Interference Angle Grinding)
- Pistons, Connecting Rods, and Ring Installation
- Cylinder Block Boring and Honing
- Main Bearing Replacement and Plastigage Clearance Check
- Cylinder Head Torque Sequence
- ENGINE WIRING DIAGRAM
- HARDWARE IDENTIFICATION (Washer, Bolt, and Nut Types)
Introduction
This manual deals with specific mechanical and electrical information needed by engine mechanics for troubleshooting, servicing, repairing, or overhauling the engine. If a major repair or an overhaul is necessary, a competent mechanic should ensure that all dimensions, clearances, and torque values are within the specified tolerances. Use only Genuine Onan replacement parts to ensure quality and the best possible repair results. The wiring diagram on the last page shows how the electrical components are interconnected.
