black valve question

[d1admiral]

83 atc 185s. The intake valve is black and covered in tar looking sludge. The front valve is a little discolored, but nothing like the intake. Is this normal. Engine runs with no smoking or anything. Just wondering if I should consider a valve job or let it ride as is.

[Mobular]

I would assume that you have the engine apart. Stand the head up so that the intake port is poting to the ceiling. Pour gas into the intake runner. If it holds the gas without leaking, everything's ok, If it leaks, have a valve grind done.

[d1admiral]

Naw, I noticed when I did a carb rebuild. Engine is still in. What do you think now?

[samster143]

If it works, don't fix it. If you take it apart, have a new valve put in... The intake valves are usually the ones to go first. I sent mine to a guy out of Dirt Wheels for a valve job....$50 plus parts, (valves cost about $20ea I think) Not too expensive, and he did a nice job. On a running bike, I would expect that the valves would always appear to be dirty. Just my opinion... I hope it runs nicely for ya!