[bikrbob]

Just picked up a 2001 gl1800 with 20k, the former owner was military I was told so he didn't ride it much. The first few tanks of mostly city riding I am getting 38-40mpg, is this normal?
The exhaust smells like rotten eggs, kind of like when a cat is going bad. I changed out the mufflers because of some surface rust and noticed the pipes were black and sotty inside.
Could the oxygen sensors be going bad? With todays gas I would not be surprised. Other than that the bike runs great, it does have some valve noise but it was supposedly serviced at the dealer were I bought it.

 

[Dookoo]

If you say it runs great and gets 38-40 mph (which is normal) but smells bad, I would also think that the cats may need replacement. Run a few more tanks through it with some highway driving and see if it improves.

 

[bikrbob]

I will try that, I talked to several owners before buying and I heard anywhere from 38-48. When I removed the old mufflers there was alot of rattling inside of them, I am guessing it was rust.