Carbon build up on center intake valve? (20v)

[Grant #2]

A few of us in the states are noticing on imported 20Vs (all blacktops so far) that there is a ton of carbon build up on the center intake valve. I didn't even look at my engine before I dropped it in.

Any ideas what causes this? I'm lacking the peak hp that I thought I would get after the swap (mid-range is good!) and I'm wondering if that is part of the problem.

http://www.ae86drivingclub.com.au/dcimages/2/7/3/6/62641.jpg

Pretty gnarly huh?

wow, a youtube button? This forum has all the bells and whistles doesn't it! :bones:

[H8CHIR6KU]

maybe try some subaru top end cleaner and see how it goes after that

but more than likely if its just that valve i think it would be due to leaking valve stem seals