I took off my header and see that there is lots of carbon build up on the exhaust valve exit. Is it okay to scrape it all off? Spray it with some simple green to clean it?
Thanks

 

use some brake cleaner from your local parts store and a rag...

 

I wouldn't spray any detergents inside my head, oil and degreasers dont mix well. It will wash the oil of your cylinder walls and thats never good. I had the same problem but I took the head of and took out the valves.

 

^ Im with him.

Ask youself this, what does it matter, your gonna get more cabon build up when you start driving again, so it really doesnt matter. Like that pretty pressure plate on you clutch, that you willl never see, it doesnt make sense to me.

 

actaully it wont do ****....#1 your exhuats valves should be closed.....if there open then done spray it down there...but get a rag and some degreaser and put the degreaaser on the rag...dont spray it....then wipe away all the carbon build up, if needed use a small brass birstle brush to help loosen some of the crap...then make sure it relatively dry...and bolt it all back up