Outline Of Strato-Charged Engine; Special Features - RedMax GZ25N Workshop Manual

1. OUTLINE OF STRATO-CHARGED ENGINE

1-1 Special Features

Unlike the conventional 2-stroke engine scavenging system, the Strato-charged Engine scavenges burnt gas by the stratified lead air scavenging method.
By creating a stratified air layer between burnt gas and the air-fuel mixture, this system significantly reduces exhaust of unburned air-fuel mixture.
Difference to the conventional 2-stroke engine is its very simple construction applying a new carburetor for independent intake of the air and the air-fuel mixture, an insulator, lead air intake tubes, and reed valves, etc.
By the stratified lead air scavenging system, the Strato-charged Engine reduces
unburned air-fuel mixture exhaust to about 1/3 of the conventional 2-stroke engine
level.
By optimizing the combustion chamber design, ignition plug position, and ignition
timing, lean burn operation became possible.
By combining with the stratified lead air scavenging system, pollutant contained in the
exhaust was reduced and fuel consumption was reduced by 30% without reducing the
power.
Unit : g/HP•h (g/kwh)
400
(544)
280
(381)
171.2
(232)
139.1
(189) 5.3
(7.2)
54
(73) 49.5
(67)
1.5
(2.0)
THC + NOx CO PM
As the catalytic converter is not applied, exhaust gas temperature increase due to the
catalytic reactive heat does not occur so that the engine heat load does not increase.
Therefore, same level of durability and reliability with the conventional engines are
assured.
A large size silencer and a muffler were employed and the noise level was reduced by
5 dB(A) compared to the conventional 2-stroke engines.
Current Engine
1.0
(1.3)
Tier 2 regulation
Strato-Changed Engine
Insulator
Carburetor
STRATO CHARGED ENGINE GZ25N
Lead Air Intake Tube (each side)
Reed Valve (each side)
2