O.S. engine MAX-21XM User Manual

It is of vital importance, before attempting to
operate your engine, to read the general
'SAFETY INSTRUCTIONS AND WARNINGS'
section on pages 2-3 of this booklet and to
strictly adhere to the advice contained
therein.
Also, please study the entire contents of
this instruction manual, so as to familiarize
yourself with the controls and other
features of the engine.
Keep these instructions in a safe place so
that you may readily refer to them whenever
necessary.
It is suggested that any instructions
supplied with the model radio control
equipment, etc., are accessible for checking
at the same time.
•
•
•

O.S. engine MAX-21XM Specifications

General

Brand	O.S. engine
Model	MAX-21XM
Category	Engine
Language	English

Summary

Safety Instructions and Warnings

General Warnings

Critical safety advice regarding propellers, fuel, and heat.

Operational Notes and Precautions

Engine Installation Procedures

Fitting the Glowplug

Guide on correctly installing the glowplug into the cylinder head.

Carburettor Installation

Instructions for securely fitting the carburettor into the intake boss.

Basic Engine Parts Identification

Piping, Installation, and Linkages

Piping Connections

Details on connecting water inlet and oil transfer tubes.

Hull Installation

Steps for securely mounting the engine to the boat's transom.

Linkage Setup

Guidance on setting up steering and throttle linkages for proper control.

Fuel and Glowplug Information

Fuel Recommendations

Advice on using appropriate commercial model two-stroke engine fuel.

Glowplug Function and Selection

Explains the role of the glowplug and recommends specific types.

Component Maintenance and Pre-Start Checks

Glowplug Replacement

Identifies signs indicating when a glowplug needs replacement.

Flexible Drive Shaft Replacement

Step-by-step guide for replacing the flexible drive shaft.

Propeller Details

Information on the propeller's specifications and balancing.

Before Starting Engine

Crucial checks and considerations before attempting to start the engine.

Starting and Carburettor Adjustment

Engine Starting Procedure

Details on how to safely start the engine using a starter.

Carburettor Adjustment Controls

Explains the needle-valve and mixture control screw functions.

Mixture Control Valve Realignment

Procedure to reset the mixture control valve to its factory setting.

Starting Safety Warnings

Running-In (Breaking-in) Procedure

Initial Running-In Steps

Detailed steps for the initial engine break-in period.

Running-In Fuel Consumption

Guidance on the amount of fuel to use during break-in.

Water Ingestion Recovery

Procedure for recovering the engine if it ingests water.

Engine Adjustment and Tuning

Pre-Adjustment Warning

Important safety warning before making adjustments.

Adjustment Procedure Steps

Step-by-step guide for adjusting the engine's performance.

Mixture Control Adjustment

Fine-tuning the mixture for optimal running and acceleration.

Carburettor Cleanliness and Maintenance

Importance of Clean Orifices

Explains why keeping carburettor orifices clear is crucial.

Fuel Filtration Recommendations

Advice on using fuel filters to prevent contamination.

Cleaning the Needle-Valve Holder

Instructions for removing and cleaning the needle-valve holder.

Care and Maintenance

Fuel System Care

Steps for maintaining the fuel tank and filters.

Post-Operation Engine Care

Procedures for draining fuel and protecting the engine after use.

Cleaning and Lubrication

Guidance on cleaning the engine exterior and internal lubrication.

Water Damage Recovery

Refers to procedures for water ingress into engine components.

Trouble Shooting: Engine Start Failures

Key Starting Requirements

Outlines the four essential conditions for reliable engine starting.

Trouble Shooting Chart

A chart correlating symptoms, causes, and corrective actions for starting issues.

Exploded View of Engine Components

Parts List

Carburettor Exploded View and Parts List

Three View Drawing and Specifications