Help me figure out what's going on here....

Yamaha_chop

Hey guys, I was hoping to get your input as to what is going on with my engine. I just got it running a few weeks ago. My area of expertise is with newer engines, fuel injection, ect...
These motors with their carbs and points I don't know a whole lot about, so hopefully you could help me here.

The left side exhaust pipe is turning a way darker color than the right side is, and it seems to be much more hot than the right side is. I haven't actually ridden the bike yet, so all of this is just idling and revving the engine a little bit, but after I shut it down I took out the spark plugs, and the right side looks pretty normal, but the left side is kind of strange. The plug is clean around the rim, but the arm hanging over the electrode is covered in soot, and the electrode area looks like it has oil on it. I have no clue what this means.

I've included some pictures of what I'm talking about, hopefully you can take a look and see what you think.

Unfortunately I don't have a lot of info about the motor and stuff.
The serial # on the engine doesn't match the frame, so I'm not sure what year it is, although it does have points, and the carbs are the BS38's. I took them apart awhile ago and cleaned them all out, but didn't write down the #'s on the jets, so I have no idea if they're stock or not. Also the engine is running with straight pipes and no filters. Other than that, I think it's stock.
In my mind I was thinking that because I live at 3,500ft elevation, that would offset the need to go to a richer jet because of the straight exhaust. Is this wrong?

Here's the pictures, let me know what you think:

Sorry for the unclear pics of the sparkplug.
Thanks for looking
Sky

xs1961

Looks like left side is running rich or fuel not burning due to ignition problem that side - similar symptoms ..Pipes usually darken(blue/gold) due to exces fuel burning in the headers/downpipes

.ET. · Full Member Joined: Jul 22, 2008 Posts: 28

Got the same problem, bluing can also be from excessive heat, these bike don't like to idle they heat up real quick

Fergie

If the left bank was mis-firing, it would be colder than the right side, so I would say you have a problem with it going rich. Check to make sure your carbs are synced up correctly.

At 3,500ft, do you guys have trains that come up that high in altitude?

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Yamaha xs650