Scooter cranks but does not start (sometimes)

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geovie
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Scooter cranks but does not start (sometimes)

Post by geovie »

Hello, I am George and Ι have a PCX 125 MY18 that I bought in August 2020. It now has 4100km and I never had a problem and really enjoyed using it.
A month or so ago it started to act weird. At first, it needed to crank a few times to start the engine which it never did before, it was starting as soon as I pressed the button. I didn't give it enough thought since it happened 3/10 times. When it did this after eventually starting up I opened the throttle, it revved up a bit started to move then revved down(on its own). After that, it continued to operate normally.

At first, I thought it might be a problem with the gasoline so I filled up with the best fuel I could find. After the fill-up, it stopped acting up. 10 days after the fill-up, I used it for a bigger than normal trip and on my way back it refused to start. I cranked it close to 10 times and turned the key between tries but it would just crank and not start. I loosened the back brake and tried to "push start" it while also holding the ignition. My attempt was successful and I managed to start it and get back home. Since then it had started to act up again as it did before.
Because this isn't always happening I am afraid that if I take it to the dealership they will tear down the scooter not find anything and just waste everyone's time.

Has anyone had a similar problem?
What could be the cause or are there any other signs I should look for?
Thanks for reading this and sorry for my English! :D
mymitzi
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Re: Scooter cranks but does not start (sometimes)

Post by mymitzi »

English is fine..........Agree about the dealer.........intermittent problems : { Surprised you could push start it. Can you test the battery?
If it checks healthy............a loose connection on the battery sometimes can cause what you are describing.
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power-full
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Re: Scooter cranks but does not start (sometimes)

Post by power-full »

Good Morning. I had something like that... it would catch on and it was barely slow and even then it would go down...change the tow bike home and start doing a test... I always thought it was the gas pump... when I went to see the injector was completely clogged .. it was just clean and so far I have never had any stress.
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gas pump before washing,
gas pump before washing,
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https://www.facebook.com/sergiofininho
Pcx powerfull kit yuminashi 168cc
93000km 23.03.2022 dont stop..
geovie
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Re: Scooter cranks but does not start (sometimes)

Post by geovie »

mymitzi wrote: Sat Jul 10, 2021 11:02 am English is fine..........Agree about the dealer.........intermittent problems : { Surprised you could push start it. Can you test the battery?
If it checks healthy............a loose connection on the battery sometimes can cause what you are describing.
Thanks for the reply! I have checked the battery and it tests good. I was also surprised with the push start and I have now done this twice.
geovie
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Re: Scooter cranks but does not start (sometimes)

Post by geovie »

power-full wrote: Sun Jul 11, 2021 2:50 am Good Morning. I had something like that... it would catch on and it was barely slow and even then it would go down...change the tow bike home and start doing a test... I always thought it was the gas pump... when I went to see the injector was completely clogged .. it was just clean and so far I have never had any stress.
Good morning to you too! Yes, I am also suspicious of the gas pump but I know that usually the gas pump either works or not. A clogged injector checks with the fact that I was able to push start it. Maybe the "extra" vacuum in the cylinder managed to pull gas through the injector. I have to disassemble half of the scooter to get to the injector, don't I?
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power-full
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Re: Scooter cranks but does not start (sometimes)

Post by power-full »

Hello good Morning . here is the video I made to test the gas pump. as I saw that it was good, I changed the butterfly and the complete injector... the bike was immediately good.... so I went back and changed it by phases. (I changed the body of the butterfly (I assembled the original), and the tube was fine, I changed the injector (original) and we have gutters again... that is, it was my problem.... when I looked with eyes to see is that I noticed that the injector network was not visible ..hence these photos ....

Video


https://youtube.com/shorts/K76iH_T3Rac?feature=share
https://www.facebook.com/sergiofininho
Pcx powerfull kit yuminashi 168cc
93000km 23.03.2022 dont stop..
geovie
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Re: Scooter cranks but does not start (sometimes)

Post by geovie »

For any future visitors. Hello!
I looked at the injector and it looked ok. I didn't look at the fuel pump mainly because the tank was REALLY full and gas would spill everywhere. I will post if there is any update.
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Re: Scooter cranks but does not start (sometimes)

Post by geovie »

It finally died and I took it to a workshop. They told me that it was a fuel pump issue and they replaced the fuel pump under warranty. It's running fine ever since. Hope this helps someone in the future.
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