Strange finding, after I filled up the tank.

[doletotodole]

I noticed on a few occasions after I filled to top the fuel tank, PCX seems to be more powerful, starts quicker and runs like a load off its shoulder.

Is it a fact? Why is it so?

[homie]

Cold fuel on a hot day maybe? The fuel in my Buell gets so hot riding directly over the twins you can feel and hear it boiling after a long run in 80-90 degree weather. I like to top off after such a run to pull the temp in the tank back down. It's scary but nothing blows so I could see cold fuel working the ECM on a hot day with high temp bikes but scooter? Hows the weather in China this time of year? I guessing not hot enough to cause this effect.

[PCX150Rider]

I wonder if the gas cap is venting Okay. When you open it to top-off the tank it goes directly to atmospheric conditions.

[Daguang]

Just psychological effect. I noticed that too, however, the engine is perfectly warmed up before you entered the gas station not like you left home.

[mowzertron]

Psychological. You get the same effect when you clean the bike.

Clean bikes go faster.

[doletotodole]

Cold fuel on a hot day maybe? The fuel in my Buell gets so hot riding directly over the twins you can feel and hear it boiling after a long run in 80-90 degree weather. I like to top off after such a run to pull the temp in the tank back down. It's scary but nothing blows so I could see cold fuel working the ECM on a hot day with high temp bikes but scooter? Hows the weather in China this time of year? I guessing not hot enough to cause this effect.

wow, boiling, that's scary.

I noticed that in midnight and midnoon, so should not be cold fuel effect, but I will try to discriminate this in future to find any difference.

[Daguang]

Psychological. You get the same effect when you clean the bike.

Clean bikes go faster.

I feel the engine sound lighter every time I cleaned the bike.

[cold_surfer]

one theory: there is a strainer on the end of the fuel line pickup, the refueling washes away the junk caught in the filter and it takes spraying in new fuel to "wash" that screen off . The part # is 16707-K35-V01 (about $8) and it fits on the end of the fuel pump. You ALSO need to suck all the dirt and debris out of the bottom of the tank -- like with a fast siphon -- or remove tank and dump it all out, spraying it out with carb cleaner. My guess is you have dodgy filling stations with dodgy tanks on your route . I always go with the newest gas station on route because the old tanks have a lot of crap in them. at 100mpg we can splurge on gas ...

[cold_surfer]

not trying to push this vendor -- just show the pic of the fuel pickup in PCX... reference #3 part there.... http://www.hondapartshouse.com/oemparts ... /fuel-tank

[cold_surfer]

also -- run some fuel injector cleaner before changing filter so the crap is sent back to the tank. Honestly, I wouldn't mess around with crappy gas on a FI 150 with tiny orfice holes. change out that filter and clear the tank to see if it returns to normal all the time. At least run the FI cleaner additive.