Sooty Engine

[n780]

There's a 2-to-1 exhaust on my bike that meets directly under the drainplug so, in order to change the oil I must first take off the exhaust. No problem.

However, once I got the exhaust off I took a peek inside and saw that it was incredibly sooty in there. My plugs have been fouling up and I believe that I'm running rich, is this an effect of that? How much of a concern is this and will I require some manner of cleanup once I get my ratios right?

Unfortunately the picture doesn't have the range necessary to show, but I swiped my finger inside and it had a pretty good layer of black gunk on it.

 

[eil]

Yes, running rich. Especially if you have fouled plugs as well.

Main causes are incorrect jetting, or a blocked or over-oiled air filter.

 

[bwringer]

Every GS engine looks pretty much like that inside the exhaust, even the ones that are running perfectly. What I'm getting at is that soot in the exhaust tract is a very poor indicator of what's going on with the jetting -- there's always some there, and it's impossible to say what's too much.

Your plugs are a far better indicator. You mentioned you're fouling plugs, so if the plugs are coming out dry and sooty, then yep, that's an indication you're running too rich. There are many possible causes -- everything from confusion over which way the choke lever works to inappropriate jetting or clogged intake and/or exhaust.