Slow take off from stop till 15-20mph

[kcpcx]

My first inclination would be to throw the stock rollers back in there in place of the sliders and see if that fixes it. Chances are far higher that it involves the sliders than, say, the O2 sensor. Could the O2 sensor be bad? Sure. But attack the more likely things first, rule them out, then dig into the less likely causes.

At this point, unless you've already done it and I've missed it, swap the sliders for stock rollers, clean that assembly (ramps) out good where the rollers move around, reassemble, test ride.

[homie]

Guaranteed method to save yourself a shitload of faultfinding hassle and repair bills:
Sell it and buy a new one.

then the new owner will be here asking the same question

[frog13]

I'm new here , but is there a throttle position sensor somewhere ? Or perhaps a clogged injector or fuel filter....pressure can play tricks at times.

[comecamino]

Sorry for resurrect this topic, but I have to say this....

The problem are the rollers.

Dr. Pulley rollers tend to turn over inside the vario and not only in the PCX, avoiding the vario to completely open up.... so the takeoff is slow as watching grass grow.... is like trying to take off in 2nd gear.

Go back to the original 15gr round rollers, you will lose top speed but omg I know how irritating this could be when it happens.


I know this because I bought some drpulleys for a SYM Joyride200 back in 2017 and the rollers turned over after going really fast. I thought it could be a compatibility or quality issue..... Then I bought my PCX WITH this Dr.Pulley already installed, they lasted a bit longer but after a 80mile trip to the next city this damned rollers started to show the same symptoms... when I came back home I confirmed my suspicions.

So I think is not very recommendable to go fast with this rollers... Absolutely ridicolous!!! specially when this "rollers" are designed/supposed for you to go faster.....

[sendler2112]

I have 15,000 miles on DrPulley sliders in my PCX including disassembly for inspection and a belt change and never had an issue. Many people install them upsidedown unfortunately. The reduced mass increases the pulling rpm for better acceleration and the new shape increases top speed, especially after filing down the pully to allow the belt all the way to the top. I can hit 72 mph/ 115 kph.

[comecamino]

I have 15,000 miles on DrPulley sliders in my PCX including disassembly for inspection and a belt change and never had an issue. Many people install them upsidedown unfortunately. The reduced mass increases the pulling rpm for better acceleration and the new shape increases top speed, especially after filing down the pully to allow the belt all the way to the top. I can hit 72 mph/ 115 kph.

Well, wow.... this is very strange because there's no way to install those rollers upside down (unless you're blind) plus, the instructions are quite clear and they have a very specific shape.

Anyway, this is a very common issue, that happens not only with the pcx. I've read problems in vespas, and burgmans... all of them with this issue it only takes one slightly rolled over slider to screw everyhing up. Also that happened to me twice with differrent motorbike brands. Is very easy to confirm....

Once you remove the variator (very carefully in one piede) and then uncover it, you can immediately notice that one is slightly rotated... not quite but it is enough. All the others are just fine. This does not happen due to bad installation but bad design or bad luck or simply bad design thn is not completely compatible with the OEM variator



(btw i was able to reach 120kmh with 13.5gr sliders, everything else standard with the PCX 125 and 130kmh with the SYM Joyride 200i with 16gr sliders)

[iceman]

I changed my air filter and belt @ approx 18,500 (dirty filter but new made no difference that I could tell) and the belt seemed fine - ok width and no splits or such and it was the dual sided kind (ribs on both sides).
The variator plates had wear and the only issue was a squeal when dropping to low revs, at least that's when I heard it and it was annoying. Another member suggested changing these would cure it and it did.
Other than that, I was still getting 130-140mpg in warmer weather (litres in against trip miles) and had no issues - bike rode well and I still see no real difference with the new parts and clean.
So, your issues may be down to worn parts of faulty parts, but my bike with little maitenance until I was pushing the supposed life of the belt ran just fine, all year round.
Always purchase a genuine belt - none of that kevlar / fake or 3rd party crap off ebay.