1)I have this problem that my fuel consumption is so bad that i get max 200km out of a full tank(15l), i then have like 3-2litre in the tank.
i run stage 3 airbox, full leovince exhaust, PC V with a map from the forum according to my mods.

2)Sometimes when i pull real hard my bike stumbles once and picks right back up, i wonder what this is, is this a fueling or a clutch problem?

3)My fuel light on the dashboard lights up when i still have 7-8litres of fuel in the tank, is this normal or not? i think it is not logical.

xt660x from 2005 with 14k kms on it

My first thoughts are that you should try a different PCV map. Sounds like its running too rich in most areas.

Which map are you using?

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2004-2007 Yamaha XT660.R European model
AKRAPOVIC OPEN SLIP ONS
DNA STAGE 3 AIR BOX KIT

Is the one i am using, before i had the stage 3 airbox i had the same problem, i took a map according to my mods and again it was way to rich
i have a db killer in my exhausts

First thing I'd do is go back to a suitable Stage 2 map and see how things pan out.

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Ok ill try it, how to see if its a good map? Only by the color of the sparkplug?

You got any idea about the fuel light going on to soon?

Try the Stage 2 map and see if it's any better. If it is then I'll have a look at the fuel trims in the two maps and see if there is anything obvious. Looking at the spark plug will give you a very rough idea of what's going on with an air/fuel ratio but with modern fuel containing ethanol they are much harder and less reliable to read as the fuel additives leave odd coloured deposits even if the engine is running well.

As for the fuel light... they all do that! They are unreliable and inconsistent (the fuel gauge on a Z is even worse) and should only be ever used as very rough indicator that the fuel level is dropping. Best just to reset the trip and get used to how many Km you can go before you need to fill up.

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