Sudden increase in fuel consumption!

[chef]

Just had the valve service done,changed mains from 95 to 100 & the fuel consumption has gone crazy!
I havent calculated MPG yet but usually 4-5 litres (Rp 50.000) will last 150 km....today i get around 60 km from the same amount
Such an increase would be caused by changing jet ?

[cuong-nutz]

Why did you change? If you're not using all the fuel, you're just wasting money out the tail pipe.

[Motofool]

Originally Posted by chef

Just had the valve service done,changed mains from 95 to 100 & the fuel consumption has gone crazy!
.......

Is it possible that the manipulation for the jet replacement has modified the height of the fuel inside one or both bowls to the point of having some continuous leak through the float valves?

If that is true, you will have leaks as long as the engine is working and the petcock feels vacuum.
It could be small enough as not to be dripping and to evaporate instead, leaving no tracks.

I would recommend a bowls' level verification with the engine idling.
For that, you could use a transparent hose in U shape and connected to the drain of the bowl being tested.
Compare the height against the specification for your model.

[choneofakind]

This sounds dumb, but did you make any changes to the intake or exhaust before changing the jets? Or did you just add larger jets for snorts and giggles?

In my experience jetting, your mileage starts tanking when your jets are too big. If your jets are the right size for your intake/exhaust needs, you should be averaging much higher than that.

For example, even with pod filter and full exhaust, I'm able to average 60 mpg with varied (read: hooligan back roads mixed with civilized commuting) riding. I also have a very smooth running bike that responds well and make smooth power all the way to redline.