Kohler 6600 Series

Questions and Answers:

M
Michelle AllenAug 20, 2025
Why Kohler 6600 Engine loses power?
- D
  Diana HoffmanAug 20, 2025
  If your Kohler Engine loses power, start by cleaning or replacing the air cleaner element. Ensure the engine isn't overheating by allowing it to cool down. Reduce the engine load if it's excessive. Inspect and clear any restrictions in the exhaust system. Check and replace the spark plug(s) if faulty. Verify and adjust the crankcase oil level if it's too high. Adjust the governor setting if it's incorrect. If the battery is low, charge or replace it. Inspect the engine for compression issues if compression is low. Check and refill the crankcase oil if the level is low. Finally, replace the fuel with fresh quality fuel to rule out fuel issues.
M
michelle33Aug 22, 2025
What to do if Kohler 6600 Engine starts but does not keep running?
- F
  Fred CampbellAug 22, 2025
  If your Kohler Engine starts but doesn't keep running, there are several possible causes. A faulty carburetor could be the issue, so inspect and replace it if necessary. Also, a faulty cylinder head gasket can cause this problem, requiring replacement. Adjust the choke or throttle controls if they are faulty or misadjusted. Inspect the fuel pump and hoses for any malfunctions or clogs. Look for intake system leaks and repair them. Loose wires or connections that intermittently ground the ignition kill circuit can also be the cause, so tighten them. Replace the fuel with fresh quality fuel to ensure fuel quality isn't the problem. Lastly, clean or replace the fuel tank cap if the vent is restricted.
P
Patricia SmithAug 26, 2025
What causes Kohler Engine will not crank?
- L
  Lance DavenportAug 26, 2025
  If your Kohler Engine will not crank, it could be due to several reasons. The battery might be discharged, so try charging or replacing it. Inspect and replace the electric starter or solenoid if they are faulty. Check and replace the key switch or ignition switch if they are faulty. Make sure the interlock switch is not engaged or faulty. Tighten any loose wires or connections that might be grounding the ignition kill circuit. Check the pawls engagement. Finally, inspect the engine for seized components.
V
valerie34Aug 28, 2025
Why Kohler Engine starts hard?
- S
  Sarah LewisAug 28, 2025
  If your Kohler Engine starts hard, consider these potential causes: a clogged fuel line or fuel filter, which you should clean or replace. If the engine overheated, allow it to cool down. Inspect and replace the ACR mechanism if it's faulty. Adjust the choke or throttle controls if they are faulty or misadjusted. Inspect and replace the spark plug(s) if they are faulty. Replace the flywheel key if it's sheared. Inspect the fuel pump and hoses for any malfunctions. Check the interlock switch to ensure it is not engaged or faulty. Tighten any loose wires or connections that might be grounding the ignition kill circuit. Inspect the engine for compression issues if compression is low. Replace the fuel with fresh quality fuel. Finally, inspect the ignition system for a weak spark.
R
Ricardo StrongAug 30, 2025
What to do if Kohler Engine runs but misses?
- S
  Sheri HamptonAug 31, 2025
  If your Kohler Engine runs but misses, it could be due to several reasons: The carburetor might be adjusted incorrectly, so adjust it properly. If the engine has overheated, allow it to cool down. Inspect and replace the spark plug(s) if they are faulty. Inspect and correctly gap the ignition module(s) if they are faulty or improperly gapped. Check and adjust the crankshaft position sensor air gap if it's incorrect. Check the interlock switch to ensure it is not engaged or faulty. Tighten any loose wires or connections that might be grounding the ignition kill circuit. Replace the fuel with fresh quality fuel. Reconnect any disconnected spark plug leads. Secure the spark plug lead boot if it's loose on the plug. Finally, tighten any loose spark plug leads.
C
Craig MooreSep 2, 2025
How to troubleshoot Kohler 6600 that will not idle?
- S
  Samuel HoSep 2, 2025
  If your Kohler Engine will not idle, it could be due to several factors. If the engine overheated, allow it to cool down. Inspect and replace the spark plug(s) if they are faulty. Adjust the idle fuel needle(s) if they are improperly set. Adjust the idle speed screw if it's improperly set. Ensure there is an adequate fuel supply. Inspect the engine for compression issues if compression is low. Replace the fuel with fresh quality fuel. Clean or replace the fuel tank cap if the vent is restricted.
E
Ethan HughesSep 5, 2025
Why Kohler Engine uses excessive amount of oil?
- T
  Tracie BonillaSep 5, 2025
  If your Kohler Engine uses an excessive amount of oil, several issues could be responsible. Loose or improperly torqued fasteners can cause oil consumption, so tighten or replace them. Inspect and replace the head gasket if it's blown or if the engine overheated. Inspect and replace the breather reed if it's broken. Inspect and repair the crankcase breather if it's clogged, broken, or inoperative. Drain excess oil from the crankcase if it's overfilled. Use the correct oil viscosity/type. Inspect and repair the cylinder bore if it's worn. Inspect and replace the piston rings if they are worn or broken. Inspect and replace the valve stems/valve guides if they are worn.
M
Michael LongSep 8, 2025
Why is my Kohler 6600 Engine overheating?
- J
  Jonathan ChavezSep 8, 2025
  If your Kohler Engine overheats, several factors could be responsible. Start by replacing the cooling fan if it's broken. Reduce the engine load if it's excessive. Inspect and replace the fan belt if it has failed or is off. Inspect and replace the carburetor if it's faulty. Check and adjust the crankcase oil level if it's high. Adjust the fuel mixture if it's lean. Check and refill the cooling system fluid if the level is low. Also, check and refill the crankcase oil if the level is low. Inspect and clear any clogs or restrictions in the radiator and cooling system components. Replace the water pump belt if it has failed or broken. Lastly, inspect and replace the water pump if it's malfunctioning.
J
Julie WrightSep 12, 2025
What causes Kohler Engine to knock?
- L
  Leslie MillerSep 12, 2025
  If your Kohler Engine knocks, several factors could be the cause. Excessive engine load can lead to knocking, so reduce the load. Inspect and replace the hydraulic lifter if it's malfunctioning. Use the correct oil viscosity/type. Inspect the engine for internal wear or damage. Check and refill the crankcase oil if the level is low. Replace the fuel with fresh quality fuel.
T
Tracy KnoxSep 13, 2025
What causes oil leaks from oil seals and gaskets in Kohler 6600?
- C
  Christina McdowellSep 13, 2025
  If oil leaks from the oil seals and gaskets of your Kohler Engine, several causes are possible. Inspect and replace the breather reed if it's broken. Inspect and repair the crankcase breather if it's clogged, broken, or inoperative. Tighten or replace any loose or improperly torqued fasteners. Inspect and repair the piston and valves for blow-by or leaky valves. Inspect and clear the exhaust system if it's restricted.

Kohler 6600 Series Specifications

General

Brand	Kohler
Model	6600 Series
Category	Engine
Language	English

Summary

Safety

General Safety Precautions

Important warnings and precautions for safe operation and maintenance.

Specific Hazard Warnings

Details specific hazards like fuel, rotating parts, carbon monoxide, and hot parts.

Cautionary Notes

Warnings about electrical shock and potential component damage.

Maintenance

Maintenance Instructions

Procedures and warnings before performing maintenance.

Maintenance Schedule

Recommended service intervals for various engine components.

Maintenance Guidelines

Oil Recommendations

Guidance on selecting the correct engine oil based on temperature.

Storage Procedure

Steps for preparing the engine for long-term storage.

Fuel Recommendations

Guidelines for using appropriate fuel types and quality.

Specifications

Engine Dimensions - Flywheel Side

Detailed measurements of engine components from the flywheel side.

Engine Specifications

Engine Dimensions - Oil Filter Side

Detailed measurements of engine components from the oil filter side.

Dimensional Specifications

Engine Dimensions - PTO End

Detailed measurements of engine components from the PTO end.

Engine Component Dimensions

Engine Dimensions - Starter Side

Detailed measurements of engine components from the starter side.

Component Measurements

Engine Dimensions - Valve Cover Side

Detailed measurements of engine components from the valve cover side.

PRO Performance Air Cleaner Specs

Engine Dimensions (PRO) - Flywheel Side

Detailed measurements for PRO Performance Air Cleaner from flywheel side.

PRO Performance Dimensions

Engine Dimensions (PRO) - Oil Filter Side

Detailed measurements for PRO Performance Air Cleaner from oil filter side.

PRO Performance PTO Specs

Engine Dimensions (PRO) - PTO End

Detailed measurements for PRO Performance Air Cleaner from PTO end.

PRO Performance Starter Specs

Engine Dimensions (PRO) - Starter Side

Detailed measurements for PRO Performance Air Cleaner from starter side.

PRO Performance Valve Cover Specs

Engine Dimensions (PRO) - Valve Cover Side

Detailed measurements for PRO Performance Air Cleaner from valve cover side.

Engine Identification and Data

Engine Identification Numbers

Information on identifying engine model, serial, and manufacturing details.

General Specifications

Key engine specifications including bore, stroke, and displacement.

Torque Specifications

Recommended torque values for various engine fasteners.

Fastener Torque Data

Torque Specifications (continued)

Additional recommended torque values for fasteners.

Component Torque and Clearance

Torque Specifications (continued)

Further torque specifications for engine components.

Clearance Specifications

Recommended clearance values for engine parts.

Engine Clearance Data

Clearance Specifications (continued)

Detailed clearance specifications for engine components.

Component Clearance Details

Clearance Specifications (continued)

Further clearance specifications for engine parts.

Standard Fastener Torque Values

General Torque Values

Standard torque recommendations for various fastener types and grades.

Tools and Aids

Separate Tool Suppliers

Contact information for obtaining specialized tools.

Tools List

Description and part numbers for essential service tools.

Service Tools and Aids

Tools List (continued)

Additional service tools and their specifications.

Aids and Lubricants

Recommended lubricants and aids for engine service.

Troubleshooting

Troubleshooting Guide

General advice for diagnosing and resolving engine problems.

Engine Cranks But Will Not Start

Common causes and solutions for engines that crank but don't start.

Engine Starts But Does Not Keep Running

Troubleshooting steps for engines that start and stall.

Troubleshooting Engine Issues

Engine Loses Power

Identifying causes for reduced engine power output.

Excessive Oil Consumption

Troubleshooting steps for engines using too much oil.

External Engine Inspection

Procedure for inspecting the engine's exterior condition.

Engine Diagnostics

Crankcase Vacuum Test

Procedure for testing crankcase vacuum for proper engine function.

Engine Performance Tests

Compression Test

Method for testing cylinder compression.

Cylinder Leakdown Test

Procedure for assessing cylinder leaks.

Air Cleaner and Intake System

Air Cleaner System Overview

Overview of the air cleaner system and its components.

Air Cleaner Components

Identification and description of air cleaner parts.

Air Cleaner Service

Instructions for servicing air cleaner elements.

Air Intake System Maintenance

Air Cleaner Base Removal

Steps for removing the air cleaner base assembly.

Breather Tube Connection

Ensuring proper connection of the breather tube.

Air Cooling System

Importance of proper engine cooling and maintenance.

Fuel System

Fuel System Components

Overview of typical fuel system parts.

Fuel Pump Replacement

Step-by-step guide for replacing the fuel pump.

Fuel System Tests

Diagnostic tests for fuel system issues.

Carburetor System

Carburetor Components

Identification of Keihin and Walbro carburetor parts.

Carburetor Troubleshooting Checklist

Initial checks for common carburetor-related engine problems.

Carburetor Troubleshooting and Circuits

Carburetor Troubleshooting

Common causes and solutions for carburetor issues.

Fuel Shut-off Solenoid Test

Procedure to test the fuel shut-off solenoid's function.

Carburetor Circuits Explained

Explanation of the float, slow, and main carburetor circuits.

Carburetor Adjustments and Service

Carburetor Adjustments

Procedures for adjusting idle and high speed RPM.

Carburetor Servicing

Steps for disassembling and cleaning the carburetor.

Float Setting (Keihin Carburetors)

Guide to setting the float level on Keihin carburetors.

Carburetor Specific Procedures

Keihin Carburetor Repair

Detailed steps for servicing Keihin carburetors.

Walbro Carburetor Service

Steps for servicing Walbro carburetors.

High Altitude Operation

Considerations for operating the engine at high altitudes.

Smart-Choke System

Smart-Choke System Overview

Explanation of how the Smart-Choke system operates.

Smart-Choke Components

Identification of Smart-Choke system parts.

Smart-Choke Troubleshooting

Diagnosing issues related to the Smart-Choke system.

Thermostat Information

Thermostat Identification

Identifying different types of thermostats used in the system.

Adjustable Thermostat Procedures

Adjustable Thermostat Details

Details on the adjustable thermostat and its operation.

Adjustable Thermostat Reset

Procedure for resetting the adjustable thermostat.

Dual Position Thermostat

Dual Position Thermostat Information

Information on the dual position thermostat.

Dual Position Thermostat Installation

Steps for installing the dual position thermostat.

Smart-Choke Starting Procedure

Starting Engine with Smart-Choke

Procedures for starting an engine equipped with Smart-Choke.

Electronic Choke (eChoke) System

eChoke System Overview

Overview of the eChoke system.

eChoke Components

Identification of eChoke system parts.

eChoke System Diagnostics

eChoke System Standard Checks

Basic checks for troubleshooting the eChoke system.

eChoke Blink Codes

Understanding and interpreting blink codes for diagnostics.

eChoke Operational Tests

Operational Tests

Sequence of operations and expected MIL lamp status for eChoke.

eChoke Failure Modes

Diagnostic information for detected failure modes in the eChoke system.

eChoke Troubleshooting

Troubleshooting eChoke Causes

Common causes and solutions for eChoke system issues.

eChoke Engine Starting

Starting Engine with eChoke

Procedures for starting an engine with the eChoke system.

Throttle and Governor Controls

GovernorThrottle Control Connections

Diagram showing connections for governor and throttle controls.

Throttle and Choke Control Systems

Unitized Throttle and Choke Control

Explanation of the combined throttle and choke control system.

Throttle Cable Adjustment

Steps for adjusting the throttle control cable.

Starting with Unitized Controls

Procedure for starting engines with unitized throttle/choke controls.

Governor System

Governor Overview

Explanation of the governor's function and design.

Governor Components

Identification of governor system parts.

Governor Adjustments

Warnings and initial adjustment procedures for the governor.

Lubrication System

Lubrication System Overview

Description of the engine's lubrication system.

Oil Recommendations

Guidance on selecting engine oil.

Check Oil Level

Procedure for checking the engine oil level.

Oil Sentry System

Oil Sentry System Testing

Explanation and testing of the Oil Sentry™ system.

Electrical System

Spark Plugs

Information on spark plug inspection, types, and service.

Spark Plug Service

Procedure for removing, cleaning, and installing spark plugs.

Ignition and Battery Systems

Spark Plug Conditions

Visual indicators of spark plug condition and causes.

Battery Maintenance and Testing

Guidelines for battery maintenance and testing.

Electronic Ignition Systems

Overview of electronic ignition system design and maintenance.

Ignition System Diagrams

Ignition Systems Overview

Description of capacitive discharge and MDI ignition systems.

Electronic Ignition Wiring Diagram

Diagram illustrating the electronic ignition system wiring.

Smart-Choke Ignition Wiring

Ignition System Wiring Diagram (Smart-Choke)

Wiring diagram for ignition systems with Smart-Choke.

Ignition System Testing

Electronic Ignition System Tests

Procedures for testing electronic ignition systems.

Test for Spark

Method for checking spark output on engine cylinders.

Charging System Testing

Battery Charging System Guidelines

General guidelines for the battery charging system.

Rectifier-Regulator Testing

Procedures for testing the rectifier-regulator component.

Battery Charging System Diagnostics

Charging System Testing Procedures

Diagnostic tests for charging system performance.

Starter System

Troubleshooting Starting Difficulties

Common problems and solutions for starting the engine.

Inertia Drive Electric Starters

Explanation of inertia drive starter operation.

Solenoid Shift Starters

Solenoid Shift Starter Components

Identification of solenoid shift starter parts.

Starter Disassembly

Steps for disassembling the solenoid shift starter.

Brush and Spring Inspection

Inspecting starter brushes and springs for wear.

Starter Motor Service

Armature Inspection

Inspecting the starter armature for wear or damage.

Brush Replacement

Procedure for replacing starter brushes and springs.

Starter Reassembly

Steps for reassembling the starter motor.

Starter Solenoid Testing

Solenoid Tests

Procedures for testing the starter solenoid's actuation and continuity.

Emission Compliant Systems

Evaporative Emission System

Overview of the carbon canister system.

Evaporative System Operation and Maintenance

How the system works and its maintenance.

Secondary Air Induction Systems

Secondary Air Induction System Overview

Explanation of twin and single secondary air induction systems.

SAI System Operation and Maintenance

How the SAI system works and its maintenance.

SAI Inlet Screen Service

Inlet Screen Service

Instructions for removing, cleaning, and reinstalling the inlet screen.

Disassembly and Inspection

Safety Before Disassembly

Safety precautions before starting disassembly.

External Engine Components

Identification of external engine components for disassembly.

Engine Component Removal

Spark Plug Removal

How to remove spark plugs from cylinder heads.

Oil and Filter Removal

Steps for draining oil and removing the oil filter.

Blower Housing Removal

Steps for removing the blower housing and baffles.

Component Disassembly Procedures

Air Cleaner and Carburetor Removal

Procedure for removing air cleaner and carburetor.

Electric Starter Motor Removal

Steps for removing the electric starter motor.

Ignition Modules Removal

Steps for removing ignition modules.

Manifold and Head Component Removal

Intake Manifold and Rectifier-Regulator Removal

Procedures for removing intake manifold and rectifier-regulator.

Cylinder Head Components

Identification of cylinder head components.

Cylinder Head Disassembly

Valve Cover and Cylinder Head Removal

Steps for removing valve covers and cylinder heads.

Cylinder Head Disassembly

Procedure for disassembling cylinder heads.

Valve Inspection and Guides

Valve Details Inspection

Inspecting valve components for wear and damage.

Valve Guides Inspection

Checking valve guides for wear and clearance.

Valve and Flywheel Components

Valve Seat Inserts

Information on valve seat inserts and their reconditioning.

Lapping Valves

Procedure for lapping engine valves.

FlywheelIgnitionBreather Components

Identification of flywheel, ignition, and breather components.

Crankshaft and Flywheel Removal

Flywheel Assembly Removal

Steps for removing the flywheel, fan, and debris screen.

Stator and Backing Plate Removal

Procedures for removing the stator and backing plate.

Breather Reed Assembly Removal

Steps for removing the breather reed assembly.

Governor and Oil Pump Service

Governor Gear Assembly

Procedures for governor gear assembly inspection and disassembly.

Oil Pan Assembly Removal

Steps for removing the oil pan assembly.

Oil Pump Assembly Procedures

Procedures for oil pump assembly disassembly, inspection, and reassembly.

Camshaft and Connecting Rods

Camshaft and Valve Tappets Removal

Steps for removing camshaft and valve tappets.

Camshaft and Tappet Inspection

Inspecting camshaft and valve tappets for wear.

Connecting Rods and Pistons Removal

Steps for removing connecting rods with pistons and rings.

Piston and Rings Service

Piston and Rings Inspection

Inspecting pistons and rings for wear and damage.

Cylinder and Crankshaft Service

Install New Piston Rings

Procedure for installing new piston rings.

Crankshaft Removal and Inspection

Steps for removing and inspecting the crankshaft.

Cylinder Bore Honing

Procedure for honing the cylinder bore.

Piston-to-Bore Clearance

Piston-to-Bore Clearance Measurement

How to accurately measure piston-to-bore clearance.

Reassembly - Initial Steps

General Reassembly Notes

Important notes and precautions before reassembling the engine.

Flywheel End Oil Seal Installation

Steps for installing the flywheel end oil seal.

Breather Cover Installation

Procedure for installing the breather cover and filter.

Reassembly - Crankshaft and Governor

Governor Cross Shaft Installation

Steps for installing the governor cross shaft.

Crankshaft Installation

Procedure for installing the crankshaft into the crankcase.

Reassembly - Rods, Camshaft, and Oil Pump

Connecting Rods and Pistons Installation

Steps for installing connecting rods with pistons and rings.

Valve Tappets and Camshaft Installation

Procedure for installing valve tappets and camshaft.

Reassembly - Oil Pan and Seals

Oil Seal in Oil Pan Installation

Steps for installing the oil seal in the oil pan.

Oil Pan Assembly Installation

Procedure for installing the oil pan assembly.

Reassembly - Flywheel and Stator

Breather Reed Cover Installation

Steps for installing the breather reed and cover.

Stator and Backing Plate Installation

Procedure for installing the stator and backing plate.

Flywheel and Fan Installation

Steps for installing the flywheel and fan assembly.

Reassembly - Cylinder Heads

Cylinder Head Installation

Procedures for installing the cylinder heads.

Valve Stem Seals

Information on installing valve stem seals.

Valve Clearance Adjustment

Adjust Valve Clearance

Procedure for adjusting valve clearance.

Reassembly - Covers and Plugs

Valve Cover Installation

Steps for installing valve covers using RTV sealant.

Spark Plug Installation

Procedure for installing spark plugs.

Reassembly - Ignition and Manifold

Ignition Modules Installation

Steps for installing ignition modules.

Intake Manifold Installation

Procedure for installing the intake manifold.

Cylinder Baffles Installation

Procedure for installing inner and outer cylinder baffles.

Reassembly - Carburetor

Carburetor Installation

Steps for installing the carburetor.

Carburetor Installation with Smart-Choke

Procedure for installing carburetor with Smart-Choke.

Reassembly - eChoke and Governor

Carburetor Installation with eChoke

Steps for installing carburetor with eChoke system.

External Governor Controls Installation

Procedure for installing external governor controls.

Reassembly - Controls and Starter

Governor Lever and Throttle Linkage Installation

Steps for installing governor lever and throttle linkage.

Electric Starter Motor Installation

Procedure for installing the electric starter motor.

Blower Housing Installation

Steps for installing the blower housing.

Reassembly - Fuel Pump and Testing

Fuel Pump Installation

Steps for installing the fuel pump.

Oil Filter and Oil Installation

Procedure for installing the oil filter and filling with oil.

Testing Engine

Procedure for testing the reassembled engine.

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Table of Contents

Questions and Answers:

Kohler 6600 Series Specifications

Summary

Safety

General Safety Precautions

Specific Hazard Warnings

Cautionary Notes

Maintenance

Maintenance Instructions

Maintenance Schedule

Maintenance Guidelines

Oil Recommendations

Storage Procedure

Fuel Recommendations

Specifications

Engine Dimensions - Flywheel Side

Engine Specifications

Engine Dimensions - Oil Filter Side

Dimensional Specifications

Engine Dimensions - PTO End

Engine Component Dimensions

Engine Dimensions - Starter Side

Component Measurements

Engine Dimensions - Valve Cover Side

PRO Performance Air Cleaner Specs

Engine Dimensions (PRO) - Flywheel Side

PRO Performance Dimensions

Engine Dimensions (PRO) - Oil Filter Side

PRO Performance PTO Specs

Engine Dimensions (PRO) - PTO End

PRO Performance Starter Specs

Engine Dimensions (PRO) - Starter Side

PRO Performance Valve Cover Specs

Engine Dimensions (PRO) - Valve Cover Side

Engine Identification and Data

Engine Identification Numbers

General Specifications

Torque Specifications

Fastener Torque Data

Torque Specifications (continued)

Component Torque and Clearance

Torque Specifications (continued)

Clearance Specifications

Engine Clearance Data

Clearance Specifications (continued)

Component Clearance Details

Clearance Specifications (continued)

Standard Fastener Torque Values

General Torque Values

Tools and Aids

Separate Tool Suppliers

Tools List

Service Tools and Aids

Tools List (continued)

Aids and Lubricants

Troubleshooting

Troubleshooting Guide

Engine Cranks But Will Not Start

Engine Starts But Does Not Keep Running

Troubleshooting Engine Issues

Engine Loses Power

Excessive Oil Consumption

External Engine Inspection

Engine Diagnostics

Crankcase Vacuum Test

Engine Performance Tests

Compression Test

Cylinder Leakdown Test

Air Cleaner and Intake System

Air Cleaner System Overview

Air Cleaner Components

Air Cleaner Service

Air Intake System Maintenance

Air Cleaner Base Removal

Breather Tube Connection

Air Cooling System

Fuel System

Fuel System Components