How to get rid of carbon buildup on intake valves?

Hi,

When looking down my intake runners today I saw a good amount of carbon buildup on my intake valves. Is there a way to get rid of it without removing the heads? Additives? Anything else?

Thanks, Michail

get the engine up to operating temp and run water down the carb dont kill it small streem, when the water hits the hot carbon it will crystallize it and fall off. Ever see a cyl. that had a water leak into it for a while looks steem cleaned