I bought an Omegasonics ultrasonic unit 2 years ago and have only nice things to say about the unit and its results. A friend who is a clockmaker has 7 of these cleaners with progressively cleaner solvent so parts are cleaned in one, then another, etc until they are in virtually pure solvent. This level of cleaning is nescessary for watches & clocks, but not for carburetors. Don has been using his Omegasonics units daily for 7-8 years and has had only 1 failure- and the company replaced that unit even though it was out of warranty. That's what made me choose this brand. These aren't cheapies-they're about as high end as they come. I started off using Simple Green diluted about 25:1 and liked how shiny the carbs came ot, but the really nasty accumulated varnish remained in many areas. I then switched to an ammonia based solution that clockmakers and jewelers use. I run my cleaner at 135 degrees F. All the ammonia solution did was make my eyes water- it 5was awful to be around. So much for that idea. The ammonia cleaner was quickly tossed. I then tried Gunk- the stuff that comes in the gallon can with the little wire basket. I have had the best success with this solution. Here in DC, we've had 3 huge snowstorms and customers are dragging snowblowers out of their sheds that have had gas left in them since Reagan was in office. Needless to say, these carburetors look like they're full of green jello. 20-30 minutes soaking, then 12 minutes with the sound on makes them run like new. I do not use this Gunk solution on carburetors with check valves- my friends at Stihl say this can ruin the valves. I probably overhaul 15-20 carburetors per week and have yet to replace one since I bought the ultrasonic cleaner. Money well spent. I overhaul about 3 or 4 saw carburetors each week and use the Gunk solution sparingly- just short dunks hoping I don't damage a check valve. So far, so good. One thing you have to be careful about is leaving carbs soaking for more than an hour- the steel parts turn grey. This can be prevented by separating the steel and aluminum parts, but this is a cosmetic issue, it doesn't affect the carb's performance. I have yet to find a cleaning solution that works well for all carbs with all types of cleaning needs, but I'm happy with what I've discovered thus far.
