It is more likely something other then the valve guides. With it idling pull one plug wire at a time & note how much it effects the idle. The cyl. that does not change is the one with the problem. Pill the plug & read it for carbon or oil fouled. Check compression on this cyl. Make sure you have some valve clearance on the valves for that cyl.
That should give you a good start to figuring the problem.
George
Last edited by Wrenchbender Ret.; 04/07/2019 7:09 PM.
