Motorcycle Repair: harley davidson sportster, jet size, gas mileage

Question
I have an original harley davidson carburetor on a 1988 Sportster 883 1100.  The jets in the carburetor were replaced to give the bike more power when it was converted to an 1200 10 years ago.  As I am getting poor gas milage, I would like to change the jets.  My questions are; what type of jets should I buy for the best milage performance and will this change in jet size effect any other modifications that were made on the bike when converted to a 1200?

Answer
First I would ask you how does the bike run right now, if the answer is great then I wouldn't touch anything. To get more power ie.. 1100 to a 1200.. it takes more fuel. But if its bogging down upon acceleration then you probably need a jet size or 2 smaller on the low speed jet. On the other hand if your putting out smoke or your riding buddys behind you can smell gas at a constant speed of about 60 mph then you probably need to reduce the main jet a size or 2. The main jet would be your gas mileage reducer also.