So on my '93 EX500 I'm getting like 17-20 MPG around town. Does something need tuning or is that just what I get for buying an old bike?

 

I don't think even a s*itty running 500 could get that kind of mileage. Are you sure there isn't a fuel leak somewhere?

 

Yeow!
Is your bike stock? (Did the previous owner put in a jet-kit or something?)
If your sparkplugs are black, or if the bike starts and runs fine cold WITHOUT the choke, then you are indeed too rich.
Do you smell gasoline?
For how long has the bike been getting terrible mileage like this? (If it's only one tankful, you might have accidentally re-set the tripmeter, which would give you an erroneous average MPG.)
Good luck and let us know!
-CCinC

 

I agree with Chris, check the spark plugs, (how long has it been since an oil change?), clean the air filter and check for fuel leaks

maybe your carburetors are screwed to hell and back also

And dont forget to control your wrist, if youre gunning it everywhere dont expect good gas mileage

 

the bike is stock.

I changed the oil in october, and I don't take it out that much for long periods of times.

It sometimes starts cold without the choke.

I don't smell any gas when it's just sitting.

The previous owner said that he got around the same mileage, so I'm assuming it's been a while.

Could it just need something tuned up?

 

One other thing to consider is how are you riding her; are you running red line all the time, meaning are you hauling a$$ from light to light or are you just ridding normal?

17 -20 is is real low for sure.

 

If it starts and idles just fine with no choke, that is usually an indicator that the pilot screws are backed out too far (and if the previous owner's been diddling with that, I would also suspect a jet-kit.
Running the poop out of a stock bike will not get the mileage that low. I always back out the pilot screws about 1/4 to 1/3 of a turn more than the stock setting, but I still have to ride the living pi$$ out of it to get worse than 50mpg.
And it appears to be the same story with my new 500: screws backed out, had a fun morning at Palomar (but still taking it easy because I just got the odometer past 1000 miles and the bike is still breaking in) and got 56.5 mpg.

How long has the bike been getting terrible mileage like this? (If it's only one tankful, you might have accidentally re-set the tripmeter, which would give you an erroneous average MPG.)

 

as calamarichris stated

 

I'll try screwing in the pilot screws. thanks for the tips. I'll update y'all on how it worked

 

OK so it is said that the pilot screws should be backed out 1/4 to 1/3 of a turn. So from screwed in what is the stock setting?