Stratified Vs Homogenized Charge; Homogenized Charge - Mercury 150 EFI Service Manual

Stratified vs Homogenized Charge

At certain operating conditions, DFI engines use a stratified charge inside the combustion
chamber to aid in reducing emissions. All other models exclusively use a homogenized
charge. The difference between the two is:

Homogenized Charge

A homogenized charge has the fuel/air particles mixed evenly throughout the cylinder.
This mixing occurs inside the carburetor venturi, reed blocks, crankcase and/or combus-
tion chamber. Additional mixing occurs as the fuel is forced through the transfer system
into the cylinder.
The homogenized charge has an air/fuel ratio of approximately 14.7:1 and is uniform
throughout the cylinder.
90-883728 JULY 2001
EMISSIONS
Page 3D-3