I was able to run my first race with the JS engines this last weekend both of them ran great! I ran both with P4 plugs and 7.0mm stack and EB mods 30% fuel. The buggy engine fully broke in in the 4th round of qualifying so with the mileage I was getting before I was really stoked to see what was in store for the main, unfortunately I had a front drive line failure about 7 min in to the race. My truggy engine ran great through the quals tons of power and great fuel mileage. I had a 20 min main to run with it and the plan was to pit once, and at pit time I was told I still had about 1/4 of a tank left , but then the engine fully broke in at about the 13 min mark and the next time I crashed I flames out so I had my pit guy put a quick tune up on it and when I went back out wow it really started to scream!!! I am very impressed with the power and the mileage of these engines and am really looking forward to the rest of the season running the JS race prep engines drinking EB mods fuel!!!