Carroll,

Both of my 6.4's are very strong and reliable engines. One has over 700 flights on it with no problems. One thing I would do is....call Gary at Brison and give him the serial number. Have him tell you what year the engine was made. The older 6.4's have only 2 bearings supporting the crank. The newer ones have 3 bearings. I don't know what year they made the change.

If you want some more power from it, have Gary send you a Carbon reed set to replace the metal reeds. I made this change in both of mine. The top end power gained a little, but the mid range became much smoother.

Bryan K.