Bandit 1200S range, jetting and shops

My B12 is getting worse and worse gas mileage, making less than 100 miles out of a full tank (4 gallons till reserve)
Which is less than 25 mpg, instead of the ~40 mpg as seen on road-tests.
It is also very cold blooded and has a slow throttle response.

I heard cleaning and synchronizing the carbs helps. Any Bandit owners with experience on the topic?
I was told it makes sense to jet the carbs and install a Dyno tuning kit at the same time...
Does it worth the buck? I am not interested in the extra horsepowers, all I want is a responsive bike (even when cold) and more range.

Thanks, Gabor

 

I would fix the problem and restore to factory specifications before
modifying the bike with a jet kit. Something is fundamentally wrong if the
bike is getting 25 mpg. If the engine has sat a while, it is possible the
low speed circuit (pilot) is partially plugged, which will cause very lean
running, poor cold running, but should not negatively affect mileage.
Pulling the spark plugs will tell you if a problem exists within one or all
cylinders. If one plug is sooty black, then the float level in that carb
may be too high, a jet may have come loose, etc. If all plugs are normal,
and it appears the problem is common to all cylinders, then check the
exhaust pipe color. Just rub your finger in the inside of the pipe. It
should be virtually clean, with a bit of brown/gray deposits on your finger.
It should be pretty clean. If not, and it is dark and sooty, then something
is causing the engine to run too rich, such as the choke being stuck
partially on. This would just kill fuel mileage. Make sure the choke cable
is properly adjusted and/or not loose. I would also check to make sure
there is no physical fuel leak, which could evaporate quickly on a hot
engine. Lastly, I do not know if this is a California bike or not, but make
sure the fuel cap is properly vented (or sealed as the case may be). If the
cap is to be vented, and is plugged, pressure could build inside the tank,
thereby pressurizing the float bowls, possibly raising float levels,
richening the fuel mixture.

I think if you install a jet kit, you may inadvertently fix a problem, and
then believe the jet kit "fixed" it.

- Phil

out of a full tank (4 gallons till reserve)

I want is a responsive bike (even when cold) and more range.