3rd gen guzzling gas

So I fill up the tank with approximately 17 litres (full tank) from dry...and consume all the gas in several days...

How far did I go on a tank? Well Probably less than 100 miles!!!! 136 kms to be exact..

WTF?

Air filter is clean, carbs were cleaned, Tire pressures are fine, Jet kit removed and stock jets and needles put back in...I left the old plugs in because they looked fine but didnt gap them??

I am stumped unless the valves seals are leaking or, Or the ignition is weak or something to that effect?

Solutions are greatly appreciated at this point...

 

I am not sure what a third gen gets for MPG but mine did not go very far on a tank of gas around town. I remember squeaking out 120 miles around town on it once.

 

It appears to run very nice now..but my gas mileage is something like 21mpg around town...???? It seems very poor...

When I took the carbs off it seems the intake valves in the front had some crud on them...black oily deposit...should I do the seafoam thing? Would seafoam even do anything?

 

I get 37mpg on mine (all stock) in mixed use riding and have done so with almost every tank full since new. I would do a seafoam and change the plugs (iridiums are cheap on amazon) and see where that gets you. The only time my mileage drops to 20mpg or so is on track use, but I assume you dont run full throttle all over the place. I can tell you the fuel gauge is very pessimistic as is the light. It comes on with a full gallon left. Another thing to look at (instead of seafoam or after it's thru the system) is BG44K which will clean up the valves etc. If you still have issues, would suggest a valve adjustment/check

 

It does seem really low to me. I used to get 120 miles, just shy of 200 kms, per tank and the bike was jetted and piped. Something is wrong, is there any reason to suspect the float height or other carb mods that may have been done?

I thought that was bad at the time and I was really happy when I got a fifth gen and the range was about 50% more per tank.