Excessive gas usage/ Idling problem

[Bratcat]

Hi All,
A funny thing happened today (not really) Gassed up the bikes, my bike took $10.00 worth, his bike took $5.00. Now we had gassed up the run before at the same time and went the same distance. We both have VTX's 1300 R, and our gas usage is normally the same. Why would my bike use more fuel? At the same time I noticed that my bike is idling very badly, if I'm not heavy on the throttle it dies off.
I would appreciate any ideas you could throw my way, We were going on a small road trip in 5 days and it would be a shame to miss out, or worse... have to ride pillion. Nothing wrong with that for someone who has never controlled their own machine before, but for me it wouldn't be nearly as much fun.

Thanks

[BuzZz]

It could be a bad temp pick-up making the computer think the engine is always cold, making it fuel it like it is always in 'warm-up' mode.

Or a really dirty/blocked air filter.

Or a dead cylinder..... but that should be more obvious.

[Wrider]

I'm with Buzzz on the bad temp sensor and/or the air filter.