Enough talking about it, time to do something!

[axy]

Ever cleaned the carb?
(Dizne se zacepe isto.. sve dize potrosnju).

No, never. 19K now.
I doubt it's that, I will check it next time. When I checked any of my scoots around that mileage, carb was "crystal clear". However, I will also check gasoline filter (was clogged up on Agility around the same mileage) and that stupid secondary air filter that is under the floorboard, so you have to spend the whole day tearing up the scoot to get it (I swear, mentally hendicapper engineers were involved in construction of Kymco's, or it was done on purpose so only mechanics can do the work).

Also, there are no symptoms of jets being clogged up, it rides flawlessly. It just ONE DAY, from one to the other fill up, decided to jump from 3.7-4.0 l/100 km (in the first 17.000 kms) to 5.0+ l/100 km (after that).

That's quite strange, because if I go all crazed-Cortez-*-ape-sh**-low-consumption-mode on my 110 hp car, I can reach 6.5 l/100 kms, which is a bit more than with the stupid thumper.

X-Files.

[zombie]

If the carb were to blame the mileage may go up as you would lean the mix, and feel the needed extra throttle. A vacuum leak may be involved (coupler) or cvt components worn. You would need to apply more throttle to obtain the same speed.
I would spend that one whole day taking it all apart, and inspecting/measuring.
The most probable is the air filter tho. or a restriction inside the air tubes. That is the same symptom that started the Ethanol/rubber thread.
Sorry Axy... May it be that you got bit in the arse?

[Cortez]

My first tank was horrid too. I thingk what ever fuel and stabizing agents they used etc. caused horrid milage. My other mild mods helped MG as well, a good synthetic in the engine and FD along with the Irridum plug.

If you go by Fuelly I get towrds the top of the MPG range...............

2nd tank worse then 1st, 48mpg.
Still very cold here, a lot of idling and only city riding.

[zombie]

I didn't think to include the auto choke. It works off a needle being raised/lowered into a fuel "port" a grain of sand may be lodged in the port, or the choke just may be defective. It works the same as a thermostat in all modern engines. It is a wax container that expands, and contracts by way of an electric heating element vs ambient engine temp. Just cause the element "tests" fine does not mean it is working. The choke is an inexpensive part so I would try replacing it to test it.
Other factor: Is the 300i a fuel injected scoot? Then there is no choke but an idle air controller.
The issue here may be the cold dense air is forcing the O2 sensor to enrich the fuel circuit to compensate for the "leaner" charge. This would not be a flaw or defect... Just the nature of fuel injection. As the weather warms this will subside.
A cool "trick" is to wrap the exhaust pipe w/ Header Tape 1 foot before, and after the O2 bung This will retain the heat, and fool the sensor into leaning the mix. Sorta like blocking the radiator on diesel engines. Warmer engines require less fuel so tricking the controller will bring the mileage up

[Cortez]

Cool, you know your way around this stuff.
I guess I'll just wait a few more tanks, and 1st oil change, the weather is
gonna get warmer too.

Both tanks were in sub-freezing temperatures.

[zombie]

"Both tanks were in sub-freezing temperatures."
Well I guess that 'splians" that Lucy.

[Cortez]

"Both tanks were in sub-freezing temperatures."
Well I guess that 'splians" that Lucy.

Yeah, I hope it's down to that little thing.
A lot of idling and riding with only 1 bar on the temp gauge.

[zombie]

These tiny engines don't fair as well in cold weather. Many of the forum members report troubles in the winter. Moderate days however is when they shine. (40-55* f). They run just lean enough to gain a bit of PEP.

[Cortez]

These tiny engines don't fair as well in cold weather. Many of the forum members report troubles in the winter. Moderate days however is when they shine. (40-55* f). They run just lean enough to gain a bit of PEP.

I guess we'll have to wait and see, I didn't notice such a big drop in MPG figures on my other
bikes, maybe 10% tops. I'd be really surprised if I get 30% better mileage in the next few tanks,
but higher temps, oil change/break in and everything else that matter will take its toll.

I'll also be switching to dr pulley weights with the first oil change.