I've been using Amsoils' 2 cycle 100:1 oil for a few seasons now. All with good praise. Better running engines, absolutely NO carbon buildup. I run it at about 80:1. Great product I thought. See, I bought a case of it a few seasons back. Just ran out last week. Was going right past my local LESCO, and thought, let me get some 2 cycle oil just to tide me over. Got through one 2 gallon tank mix of the Kawasaki 50:1 and my Echo String trimmer is loosing power. I look at the muffler outlet last night, and see that what is normally a 3/8" round "tailpipe" is now clogged down to maybe 1/8"!!! I got out my drill and drilled the carbon out like I used to do before the Amsoil. So, if your tired of de-carboning your 2-strokes, give Amsoil a try. Wish I would have took a picture. Maybe I will, as I have another tankfull to use up. I'm sure it'll be choked up again soon.