What was found
(CAN) DURING DIFFERENTIAL COMPRESSION CHECK IT WAS FOUND THAT NR 3 CYLINDER HAD A SEVERE EXHAUST LEAK (20/80). AFTER REMOVAL AND INSPECTION OF THE NR 3 CYLINDER IT WAS REVEALED THAT THE EXHAUST VALVE GUIDE WAS CRACKED AND BADLY WORN AS A RESULT OF THE LONGITUDINAL CRACK. IT SEEMS LIKELY THIS CONDITION WAS CAUSED BY RUNNING THE ENGINE TOO LEAN. THE SAME CONDITION WAS ALSO FOUND ON NR 4 CYLINDER (0/80) DURING THE SAME TESTS.