84 200S that's working great
 

I have a 84 200S that runs great. When I change the oil it comes out black and I was wondering if there is some type of flush that I can use that will remove the excess carbon and not damage the clutch system. Thanks as always.

84 200S that's working great
 

While it`s true some trash builds up in the crankcase due to clutch wear and etc. I`ve found it in several I`ve torn down. I would drain some oil out maybe a quarter way down, pour in some seafoam to the full mark. Then ride but not hard for about 15 minutes. Then change the oil. You`ll be surprised how black the oil is that comes out, also make sure you tilt it and let it drain at least 30 minutes. On the refill I recommend pure synthetic oil. As in most cases using regular conventional oil after as little as 2 hours of riding it`ll already be black. After switching to synthetic I can get 10 to 12 hours before the oil goes black.

84 200S that's working great
 

I am not so sure putting synthetic oil in an older engine with automatic clutch would a good move
On these engines I have found the Honda Gen 4 oil works great
I run in all my bikes
What I did was simply change oil a couple times after each weekend riding
Now when I change oil it comes out clean
Just my opinion
Stay Safe
Ray