We ran the Pixie 3 Port here but they weren't competitive on bigger tracks, however they were usually pretty reliable. Maybe 2 gallons isn't run in yet.. I now use them in a 10th Truck and they are way overkill but ultra reliable.(1hour Final no worries) I have run maybe 20 litres through mine and it still nips at tdc cold.

The LSK buggy motor was pretty ordinary at first but after about 8 litres (2 gallons) it is now as powerful and fast as any buggy motor I've seen and fuel economy is excellent.

I have just ordered some Rossi X3 .12 engines so I hope that they are as good as the LSK.