I have a OS-46sf that I have been flying all summer. Start it, fly it. Don't have to mess with it. Today it started acting up. I had three dead sticks. I haven't had 3 all summer. Seems to be running hot. I even ran it rich and it sill dead sticked. Using Omega 15%. Any suggestions as to what to look for. Needle valve was very hard to turn. I removed it and use the elect. starter to flush out the carb and needle valve.