Ok, I sunk my 2012 xmr and didn’t have time to jack with it for a year. I busted the engine down completely, had to bore the cylinders over, and get a valve job because of pitting. Now it’s back together and running like a scalded ape, but for some reason if I decel down hill agressively so that the engine brake is engaged one of the cylinders stops firing. Then I will feather the throttle and it fires back up and runs great again.. I also notice a miss at idle about every 4th rotation or so that sometimes causes a stall. Compression checks 185 front and just above 200 in the rear. Any suggestions? The bike only has 80 hrs and all other engine components looked great. Power is there as should be. I put about 10 hrs on it since the rebuild.