I have an OS 40la and flew it on my trainer shortly into it's 3rd season, I felt it was lacking a little. Everyone told me to take the stinking baffle out and watch how much power it would create. {this must be some sort of trick to pull on rookies, like hey watch this he'll fall for anything} I removed the baffle adjusted the needle slightly and taxied down the runway. The plane used 6 inchs less runway than before, with the grass here that ment 99ft 6in vs. 100ft. HA HA the joke was on me. I stopped at the LHS on the way home and bought a OS46AX. Now I can take off in 25ft ,but the landings were a little hotter till it broke in all the way and I could get the idle down.