cleaning out valves

[YoungRookie]

I picked up a ka24de to use for me ka-t. i took off the header, and looked in at the vlaves on the exhaust side. There is some oil buildup covering them which i would imagine would not make for a good seal, and means it would probably smoke when running. My question is, is there any way to clean out that oil build up before i install the motor? would sea foaming clean that out after i install the motor? I heard not to use that stuff on boosted motors tho. i just dont want to have to replace the head on the motor, so i just want to find a way to clean out all that oil buildup in there which i know there has to be a way. I just want to make sure i dont fuck anything up trying to clean it out so thats why i'm asking for you fellow zilvians to help me out. Thanks ahead of time.