CM 871 help please

[slowpoke]

just to mention, when mine had an (engine vibration with a slight fuel knock) turned out to be a timing actuator i started by swapping out rear metering actuator with a known good used one i had no change. put that one on front cyl. no change except now i could hear knocking at idle, put original back on still knocking then swapped out front timing actuator, knocking gone almost immediately, engine smoothed right out, pulled right down to 1150 rpm and up to 1800 rpm just to try, still no knock or vibration. but i was lucky enough to have kept two actuators as spares . there not cheap just to try out.