Thoughts on 1 of 6 intake valves looking filthy?

[Rocket Scientist]

He did, they're good.

Hmmm, when I was a young feller I bought a used V-65 Honda Magna. The first time I checked the valves they had went tight (typical). No matter how carefully I set the valves they were noisy. I made up an adapter to pump compressed air into the spark plug holes and then listened in the intake and exhaust ports, most were leaking. Pulled heads and found during the time the the valves ran tight, they got carbon build up on the faces and seats. I carefully scraped them clean then lapped the valves and blued them. After that valve train was very quiet.

The reason I wrote that novel was to put forth that maybe his suspect intake valve, has carbon holding it open some ?

 

[Claviger]

Yeah absolutely, wasn't trying to sharp shoot you. Really just needs the valve pulled to check all the possibilities out... or not, and just ride it and watch your oil level.

 

[Triple Trouble]

Compression test and leak down test?

 

[atomsplitter]

A compression leak down test would show if the crusty valve is leaking. Narrows the possibilities.