My flat land sled is an 800 Switchback. I blew a belt a few weeks ago, put a new belt on and rode it 8 miles home but over 7k the det would flash. Tried new det sensor and checked for vacuum leaks-no change. Turned out the crank broke in the pto journal but I dropped a piston before figuring that out. New crank, case done, 1 cylinder & piston etc. First ride out with it last wknd and the light still flashes. If you stay at low speeds/rpms it is fine. Was able to run wide open a few times for 5-10 seconds and then it came on. As the day went on you couldn't get over 7 period and it came on. 500 mains, needles at 4 and pto side has a shim under needle. Staked the stator before removing it so timing should be good. Running premium fuel premixed for even for the first tank. Running the key in either position doesn't change anything. Anyone got any ideas? I am going to borrow a cdi box from a friend on Sunday and see if that changes anything.