BAD gas milage

[Lonerbtw]

  All of a sudden 90 miles to reserve. Last fill up 100 mi. @ 5.1 gals. Any thoughts? Can't see any leaks and no smell. Its a 97 standard.
  Loner

[Michvalk]

Bad mileage on one tank, or more. Buy the gas from the same station all the time? Could be any number of reasons. Gonna need more info

[Firefighter]

Nothing new done? I put an inline filter in the fuel line and same thing, had to take it out. Air filter, bad gas, twist the throttle more? Wheels turn free? I guess the engine runs well? All the enrichment valves are closing correctly? Possible the fuel pick up is blocked above the reserve?  Few things that I could think of.

[Brewer]

Check the vacuum lines to the carbs (thinking out loud / or in type)

[The emperor has no clothes]

Hauling ass against a headwind ?

[The emperor has no clothes]

I would confirm mileage with a couple more tankfuls first. 

[Bighead]

I have had to hit res. at 90 on my 97 before and have gone as far as 130 before going to reserve just depends on how and where you are riding.