Most people are under the impression that a 4-stroke is cleaner, but a DFI,
such as a late model Evinrude, has fewer total emissions than a late model
EFI 4-stroke. The great thing about DFI is that its emission output stays
fairly steady throughout the life of the motor.
Could that be because the 4-stroke lasts so much longer? Sorry,
couldn't resist.
Steve
When it comes to marine engines, I'll bet there's a whole lot more old 2
strokes than 4 strokes.
I couldn't resist either.
Barry