Yikes, I was shimming my jet needles today, and I happened to glance down into the intake manifold with a light shined directly into it - this is like the 8th time I've had the carbs half-removed, but just never really looked down there before.

Holy christ, the back-sides of my valves look like crap - all brown-blackish and gunky-crusty. Is this normal? Is it a problem? If so, is there any way to clean them up besides taking the head off and taking them out?

I'd appreciate it if anyone who's had good looks at lots of valves could comment on these pics. Sorry, they're not the best, taken at night.

 

Use a good quality fuel like Chevron. Also rev the pee pee out of it occasionally.

 

Fuel isn't different, the additives that are dumped in the tanks are the only difference.
Your best bet is to run something like Sea Foam every once in a while. Add 4 oz, or a quarter bottle, into the tank at fill-up and drive the **** out of it.

 

if there is white krusty bubbles on top of the valve you may have a little water mixed with your fuel try some new fuel