Can carbon deposits around the valves affect the clearances?

[DClark]

I will be adjusting them next week and was just wondering. I dumped in a 1/4 bottle of techron and went for a ride today. It was 63 degrees today, expecting snow next weekend, be a good time for the valve adjustment.

[Wild-Bill]

If they get thick enough to keep the valves from seating then sure. Generally, though the seats stay pretty clean unless you're doing something extreme to the engine.

[hardlydangerous]

usually not. adjust them as you normally would