EasyManua.ls Logo

Tecumseh H25 - User Manual

Tecumseh H25
124 pages
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
Loading...
This manual covers engine models:
ECV100 - 120, H22 - 80, HH40 - 70, HHM80, HM70 - 100,
HMSK70 - 110, HMXL70, HS40 - 50, HSK30 - 70, HSSK40 - 50,
HT30 - 35, HXL35, LAV30 - 50, LEV80 - 120, TNT100 - 120,
TVM125 - 220, TVXL170 - 220, TVS75 - 120, TVXL105 - 115,
V40 - 80, VH40 - 70, V60 - 70, VM70 - 100
Model numbers are located on the engine shroud.
3 TO 11 HP
4-CYCLE
L-HEAD
ENGINES
T E C H N I C I A N ' S H A N D B O O K
TECUMSEH

Table of Contents

Question and Answer IconNeed help?

Do you have a question about the Tecumseh H25 and is the answer not in the manual?

Tecumseh H25 Specifications

General IconGeneral
Fuel TypeGasoline
Oil Capacity20 oz (0.6 L)
Starting SystemRecoil
Ignition SystemMagneto
Engine Type4-stroke, single cylinder, air-cooled
Max Power5.0 hp (3.7 kW) at 3600 rpm

Summary

Chapter 1: General Information

Engine Identification

Identifies engine model, specification, and serial numbers via stamped markings or decals.

Interpretation of Model Number

Explains the meaning of letters and numbers in Tecumseh engine model designations.

Engine Oil

Specifies recommended oil types, grades, and capacities for Tecumseh engines.

Tune-Up Procedure

Provides step-by-step instructions for minor engine tune-ups.

Chapter 2: Air Cleaners

Troubleshooting or Testing

Guides on diagnosing engine issues caused by a dirty or restricted air cleaner.

Chapter 3: Carburetors and Fuel Systems

Carburetor Identification

Provides simple procedures to identify different Tecumseh carburetor series.

Engine Troubleshooting

Flow chart to diagnose engine starting problems, checking for spark and fuel.

Carburetion Troubleshooting

Chart correlating air, diaphragm, and fuel system problems to engine performance issues.

Carburetor Pre-sets and Adjustment

Details pre-setting main and idle mixture screws for various carburetor types.

Final Adjustments (Non Emission Engines)

Explains how to fine-tune main and idle mixture screws for optimal engine performance.

Float Adjusting Procedure

Explains how to check and adjust the float height for proper engine starting.

Inspection

Covers inspection of carburetor components like throttle shafts, mixture screws, and fuel bowl nuts.

Assembly

Provides step-by-step instructions for assembling carburetors after service.

Chapter 4: Governors and Linkage

Troubleshooting

Guides on diagnosing governor-related engine problems like hunting or overspeeding.

Engine Overspeeding

Details immediate actions and checks for engines running at excessive RPM.

Engine Surging

Explains how to stabilize RPM and check governor adjustment for surging issues.

Governor Adjustment

Provides steps for adjusting the governor clamp on the governor lever for correct RPM.

Governor Adjustment Procedure for Short Block Installations

Explains repositioning the governor clamp for short block installations before 1977.

Governor Gear and Shaft Service

Details procedures for removing and replacing governor spool, gear, or shaft.

Speed Controls and Linkage

Covers linkage attachment points and R.P.M. checks when components are removed or replaced.

Adjusting RPM on Medium Frame Vertical Speed Control

Guides on adjusting high speed RPM by aligning slots and using a tool for tabs.

Adjusting Governed;Non-Governed

Explains setting governed idle RPM and non-governed idle by adjusting screws or tabs.

Adjusting RPM on Medium Frame Vertical

Details high speed RPM adjustment on medium frame vertical engines using a tool.

Chapter 5: Rewind Starters

Assembly Procedure

Guides on inserting rope, assembling gear, pulley, and mounting the starter.

Disassembly Procedure

Explains removing rope, handle, starter bracket, and spring capsule.

Chapter 6: Electrical Systems

Starting Circuit and Electric Starters

Describes the operation of the electric starter, including pinion gear engagement.

Charging Circuit

Explains how flywheel magnets and alternator coils induce current.

Basic Checks

Lists essential preliminary checks before extensive electrical system troubleshooting.

Troubleshooting Electrical Starter Circuit Flow Chart

Flow chart for diagnosing electric starter circuit issues, from no turn to stalling.

Troubleshooting Electrical Charging Circuit Flow Chart

Flow chart for diagnosing electrical charging circuit problems, checking voltage and diodes.

Voltage Regulators

Guides on checking voltage regulators using a voltmeter to detect overcharging.

Low Oil Shutdown Switches

Details how to check the function of the Low Oil Shutdown switch.

Inspection and Repair

Covers inspection of starter components like pinion gears, brushes, and armatures.

Chapter 7: Flywheel Brake Systems

Brake Lever and Pad

Details inspection and replacement of the brake lever and pad assembly.

Chapter 8: Ignition

Solid State Ignition System (CDI)

Describes the CDI system components and voltage transformation for spark generation.

Magneto Ignition System (Points)

Explains how flywheel magnets, coil, and points generate spark.

Identification of Tecumseh Ignition Systems

Illustrates internal, external, and solid state ignition system types.

Ignition Troubleshooting

Flow chart for diagnosing ignition problems such as no spark or erratic running.

Testing Procedure

Provides procedures for testing ignition system components like spark, air gap, and coils.

Starting Circuit

Tests for spark, checks spark plug condition, and verifies ignition switch function.

Charging Circuit

Tests coil and lamination assembly for shorts and coil operation with a tester.

Spark Plug Service

Covers spark plug removal, cleaning, adjustment, and replacement criteria.

Ignition Timing Procedure

Explains ignition timing importance and procedures for standard point systems.

Solid State Ignition Timing

Explains setting solid state ignition timing using an air gap gauge.

Chapter 9: Internal Engine and Cylinder

Lubrication Systems

Details lubrication methods for horizontal and vertical shaft engines, including oil pumps and dippers.

Engine Operation Problems

Comprehensive flow chart for diagnosing various engine operational issues.

Engine Knocks

Troubleshooting guide for engine knocking issues, covering loose parts and ignition timing.

Overheats

Troubleshooting guide for engine overheating, addressing loading, oil, and cooling fins.

Surges or Runs Unevenly

Troubleshooting guide for engine surging, covering fuel cap vent, carburetor, and linkages.

Excessive Oil Consumption

Troubleshooting guide for high oil consumption, addressing seals, gaskets, and engine wear.

Engine Misfires

Troubleshooting guide for engine misfires, covering spark plugs, carburetors, and valves.

Engine Vibrates Excessively

Troubleshooting guide for excessive engine vibration, checking crankshaft and mounting bolts.

Breather Passing Oil

Troubleshooting guide for oil passing through the breather, checking oil level and gaskets.

Lacks Power

Troubleshooting guide for lack of engine power, addressing air intake, lubrication, and exhaust.

Testing

Provides procedures for testing engine knocks, overheating, surges, misfires, and vibration.

Engine Knocks

Tests for loose fits, flywheel key damage, ignition module air gap, and carbon buildup.

Engine Overheats

Tests for engine overload, oil level, cooling fins, carburetor adjustment, and RPM.

Service

Covers engine disassembly procedures for accessing internal components.

Disassembly Procedure

Provides step-by-step instructions for disassembling the engine, including flywheel and cylinder head.

Pistons, Rings, and Connecting Rods

Covers inspection and replacement of pistons, rings, and connecting rods.

Crankshafts and Camshafts

Details inspection and timing alignment for crankshafts and camshafts.

Crankshaft Bearing Service

Covers ball bearing removal and installation for crankshafts.

Chapter 10: Engine Specifications

Four Cycle Torque Specifications

Lists torque specifications for various engine components across different models.

Engine Specifications Standard Point Ignition

Details specifications for standard point ignition systems, including timing and clearances.

Solid State and External Ignition

Provides specifications for solid state and external ignition systems, including air gap settings.

Related product manuals