I was at my Stihl dealer today and he showed me a new FS94R that he got in recently. Its 2 stroke and similar to the old style FS 76,80,85 trimmers. Only drawback is its about 30 dollars more than an FS90R 4mix. So if your not keen on the 4mix engines you have some good news with the simpler 2 stroke. Here is Stihls page on it. http://www.stihlusa.com/products/trimmers-and-brushcutters/professional-trimmers/fs94r/
So were back to the good old two stroke again?! I thought the 4mix was the way to meet EPA regulations?
It's one way to do it. Stratocharged two-strokes are another. The four-mix has met with some resistance among the pro crowd looking for a lightweight pro-trimmer. I like the FS100RX just fine but have to admit Stihl didn't have anything on RedMax or Shindawa in that department.
Yup. I have 2 of the 4 mix fs90. They run fine but compared to echo or shindy they feel like concrete blocks. 24 cc on this new one. 28 on the fs90. Does a strato make that much difference?
Strato doesn't really add power all by itself, but it will clean up a 2-stroke enough that catalytic mufflers and mini 4-strokes are not necessary. I like 'em just fine on my saws and a lightweight trimmer. The 4-Mix is amazing with big loads on it however. I have an FS110R and it is a powerhouse for it's size/weight. Put a powersweep attachment on one and you'll understand. My BR600 is a beast as well.
I think the advantage of the 2 stroke is simplicity. Not that adjusting the valves every year is a big deal, its just less moving parts. Emissions aside.
Simple he says...... Simple in terms of moving parts, indeed. But lemme tell ya, trying to understand how these engines, especially newer ones, work beyond the basics of suck squish bang and blow, is enough to make my brain hurt. Guys that modify them for even more usable power without severely compromising reliability have my utmost respect. Because when the laws of fluid dynamics are applied to these little bastards, they are anything but simple! Just try calculating an accurate compression ratio for a two-stroke.
Simple in the fact that only 3 parts move,crank, rod piston. 4mix has those 3 plus cam,2 pushrods, 2 rocker arms and 2 valves. My count is 3 to 12.
