Originally Posted by Captainbob

Two years ago I bought a Moki 250 for a comp arf F4-U i was building. Initial test running on a test stand was not satisfactory. it wasn't possible to get the high speed mixture rich enough (turn the needle out three or more turns no drop in rpm). I settled for this, finished the airplane and installed the engine and test flew. However, the Moki quit frequently, once in flight, and was just very temperamental. I started reading others comments in this forum and found out that many were having similar problems. At one point V.A. came out recommending an electric fuel pump. To me, this was an admission from the factory rep. that the engine had issues. Finally, out of total frustration, I discarded the factory Walbro carb. In it's place I used an O.S. Max 8B carb I had in my "junk box" (I believe O.S. used this on their 108 motor). GUESS WHAT! All problems disappeared. I use no pump of any kind, not even muffler pressure. The throttle response is much more linear and CH temps have dropped from somewhere around 250F to less than 200F (Jeti telemetry). I've had many flights on the Corsair since making this change and I no longer have any concerns about the engine stopping in flight or any other time.