Motorcycle Repair: Knocking and Bogging, piston slap, bike mike

Question
QUESTION: 2002 FLHR-I Roadking  88CI Stage 1 upgrade
1.) I have a loud knocking at higher rpm's.  Sounds like lifters or rockers? (thats what I would equate if a car was making the sound)  Can't get a decent answer from my HD dealer.
2)  While throttling up a low speeds the engine sometimes coughs (stutters). Feels/sounds like a pause in gas flow.  Doesn't seem to happen when the HD dealer has it.

Any opinion

ANSWER: Your cough is probably from a lean condition. Pull your plugs  and let me know what color they are.
Does the knockin sound like its coming from the right side of the bike?
Mike

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QUESTION: I'll check the plugs.  Would the lean condition also cause backfiring when throttling down (like coasting toward a stop light while in gear?).  Hard to say about the knocking.  I'll have to focus on which side next time I ride.  Thats where the pushrods are..right side.

Thank you for your time.  I'll be back on monday.

ANSWER: It can. yes the pushrods are on the right side
Mike

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QUESTION: The plug tip is grey. The threads and top of thread area is black.
The knocking does not appear to be coming from either side.

Answer
The plugs should be a tan in color, so you are not running lean. The knocking can be several things, collasped lifter, piston slap, bearing going out of the cam, rod going out. It is going to depend on where the noise is coming from.
Good luck and happy riding
Mike