Originally Posted by Ridin' Green
Stihl purchased 100K small 2 stroke strato-charged engines from Redmax to use, but since they had so much invested already in the 4 mix development, they shelved those engines and went full bore at the 4 mix believeing that the epa would eventually force all small engine manu's to follow suit. Then, much to Stihl's chagrin, the Redmax strato engines not only met, but far exceeded the epa's reg's at that time, and would do so for quite some time to come.
There's a little more to this story and it is a critical part of this story.
The EPA was considering and had drawn up draft regulations for much tougher exhaust emissions for hand held 2 stroke equipment. This was being considered for a significant number of years. These new regs were going to force literally all 2 strokes out of the business. That is why Shindaiwa, Stihl and a few others spent significant amounts of money developing their 4 stroke engines.
Then in 2008 the EPA suddenly changed their minds. The story says that the engine manufacturers said that they couldn't make their current engines any cleaner than they already were and the EPA relented and decided to keep the Tier II (the old standard) emissions levels in place.
In their explanation page of the new standards the EPA says:
"We are not adopting new exhaust emission standards for handheld emissions."
Stihl and Shindaiwa got screwed, plain and simple.