Since the beginning of Dirtweek '03, I've gone through a gallon & a half of premix. If you're not familiar with it, it's a pump that fits most standard container openings. Here's a link to Rich's review:
http://dirtrider.net/drn_tested/pump/nielsen_pump.html
I used an empty one gallon jug, as it didn't fit my one gallon container of premix. The directions are fairly clear, use so many pumps per gallon of gas for whichever ratio you want. You're supposed to prime the pump, but I could never figure out how to do that. As a result, my first 4 or 5 pumps were mostly air. You also have to pump very slowly, or you don't get a full squirt. The directions on these last two items aren't clear enough for a dummy like me. With the three weeks I average inbetween rides, I can never remember how to use it properly. Combine the first few misfires with the required 15-20 pumps needed for a full 5 gallon pit jug and I never really knew what ratio my gas was mixed at. 16:1? 100:1? Beats me. And if you're nearly out of premix, you have to make sure that there's enough premix in your container to ensure you don't start sucking air. That happened to me after getting around 10 good pumps in a full pit jug once. I had enough premix to finish, but it was a total guessing game with the remaining half air, half premix pumps I was getting.
Also, the thing leaks everywhere. It's flimsy. Not the cap or hose connections, but the pump body itself. It turned over on it's side once and premix leaked all over my box of dirt bike maintenance thingies. Definitely not as clean as a Ratio Rite, believe it or not.
Anyone want to try it out? I'm going back to my Ratio Rite. :|