I have a DA-50R and KS flex header for sale. I just had the engine serviced by DA, and it is good to go! I would guess the motor has about 20gal. through it, but don't know for sure. This engine with a KS-1060 tuned pipe was in my EF 88" extra, and worked great! Never died on me! <-except the one time I ran it out of gas;) If you can use them, I will throw in the 2.5" aluminum standoffs.