Weak acceleration. Baby fart backfire when I let off the gas

[Cortez]

That's stock setup.

The X 500 carb has max. power at 7500 rpm and max. torque at 5000 rpm,
X 500i at 7000 / 5500 rpm,
Downtown 300i at 8000 / 6500 rpm.

I doubt the Downtown has 6000 rpm at _true_ 105 kph.
If 6k rpm @105 kph, then at most 7.4k rpm @130 kph (its official top speed), would be an overdrive.
At ~100 kph the X 500 variator is still in its adjustable range, it redlines far beyond 8k rpm (I don't remember exact number).

And as "Meister Zip" once pointed out, the tach reading may be as wrong (and differently wrong from individual to individual!) as the speedo reading. He always uses his professionel engine tester.

Yeah, I just checked again, the Downtown is at 6000rpm @100kph _indicated_.
Still.. I expected no more then 5200-5300 on the XC500 at 100-110kph.. but again, my
ER6F is at 5000rpm at 110kph (indicated) so I'm obviously expecting too much.

6000rpm seems like it would use a a lot of fuel already...
I think the Piaggio Master (493ccm) based Peugeot Satelis was runing around 5000rpm
at 100kph.. but indicated again..

[ts1]

The X500 is a gas guzzler, both carb and injected.
The Piaggio or Japanese engines more frugal.
But the Downtowns 300i is state of the art.

[drifter]

And you probably got fuel consumption of a CBR Fireblade riding on a track.. 
Seriously though, I'd love to hear MPG figures from youz guys with carbed 500s!

on our econo run I got 18.++km/L computed with a GPS calculated mileage. if i were to base it on my km reading i would have gotten 21km/L. My ridding buddy got 19.++km/L.

not bad for my X500 considering i'am 240lbs my under seat storage and top box was full with tools, clothes and a gallon of h2o. we almost had the same consumption (difference of .2-.3L) until i had a little race with a honda cb 400 for a good 10km-15km!

my buddy's x500 is all stock mine had the malossi multivar, leo vince pipe and an improvised air filter.

[Cortez]

on our econo run I got 18.++km/L computed with a GPS calculated mileage. if i were to base it on my km reading i would have gotten 21km/L. My ridding buddy got 19.++km/L.

not bad for my X500 considering i'am 240lbs my under seat storage and top box was full with tools, clothes and a gallon of h2o. we almost had the same consumption (difference of .2-.3L) until i had a little race with a honda cb 400 for a good 10km-15km!

my buddy's x500 is all stock mine had the malossi multivar, leo vince pipe and an improvised air filter.

Great.. 5l/100km is as high as I'm willing to go, considering my kawasaki with almost twice the
power need less fuel then that..