Page 1 of 1

PCX suddenly won't start

Posted: Tue May 23, 2023 8:27 pm
by PcxSomething
Hi guys,

So, after many years of pretty faultless service, my 2016 PCX 125 has suddenly stopped starting. :(

Problem definitely seems electrical. I turn the key, and although the display backlight turns on, sometimes the display doesn't display anything on the LCD, sometimes it does. But when I try to start the engine, I just get a little click noise.

I also have a worry that the fuel meter, when it does show, isn't accurate, as the last time I was out on the PCX, I seemed to drive an unusually long way while the bars stay on 3 bars - I also have a slight worry I've run out of fuel because of this :o - I now think that's less likely, though.

The headlights still do come on, though, strangely.

I figure either water/damp has got into the display system (not sure that would stop it starting, though), or the battery is on it's way out - I guess at 7 years, it's had a very decent innings, if so.

Based on the "symptoms" what do you guys think it's most likely to be?

To test my dying battery theory, and as it's the cheapest option, I've ordered a 12v charger off Amazon.

Extra question on this. If I connect the 12v charger to the battery, do I need to first disconnect the battery from the bike? Could I frazzle the bike electrics if I don't (I haven't checked yet, but maybe it's physically impossible, anyway?)? Should I maybe also physically remove the battery from the bike before charging, first, just to be on the safe side?

Thanks!

Re: PCX suddenly won't start

Posted: Tue May 23, 2023 8:31 pm
by Jge64
You can leave the cables connected to the battery, (keep ign off ) but I usually just disconnect the negative cable when I’m going to charge it with a charger…

Remember, if the battery is flat, and has been flat for a considerable amount of time, -meaning more than 24 hours- , the battery is probably damaged, I would replace the battery no question, they’re not that expensive.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 6:23 am
by PcxSomething
Thanks

Well the battery isn't flat, as as I say the headlights are still coming on. It's more it won't start, and the dashboard display is being odd as well.

My HOPE is, is that the battery just isn't putting out enough juice, and that's why some things are working, and others aren't.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 3:38 pm
by PcxSomething
Well, interesting.

I've took the battery out, and there's a clear liquid on and near the contacts. I don't know if water's leaked into the compartment, or it's acid leaking from the battery. The battery case is undamaged in any way, so I don't know why it might be leaking, other than maybe it's 7 year age?

Problem is, I don't know how to test what the liquid is. I'm scared to touch it, in case it burns my fingers off. How strong is the acid in a lead acid battery?

No risk of fire or explosion, I assume?

Any ideas on what to do? Thanks.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 4:02 pm
by mymitzi
Put Baking soda on the liquid. If it's acid,it will bubble up.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 6:29 pm
by Jge64
I wouldn’t care what the liquid was, I'd get a rag and wipe it off.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 7:01 pm
by PcxSomething
Ok, false alarm. It looked wet, but I think it's more some sort of protective oil. Didn't burn my fingers, anyway. :D

Right, so progress. Looks like it most definitely is the battery.

Took the battery out, charged it with my new charger. It wasn't near flat, to be honest. Read at 75%, according to the charger. Think the amps output must be going, though.

Put it back in the bike after charging, and things worked better. Display fine, lights, fine, but....It started, after struggling a little, but on starting up the headlights go out, then come back on when it's started up. Also, when it's running, the dashboard display light and headlights are flickering slightly, constantly. Seems definitely like there's not enough power output to power everything. Strange how it's happened so suddenly, though.

In a way, I'd like to run it for a while to see if things keep improving, but I'm not sure I can risk going out on it. Think the safest bet is just to buy a new battery.

Just had a thought, if you put a magnet by the side of a lead acid battery for a long while, can it damage it?

So, new battery. Amazon.co.uk are selling a ytz8v for £76 + £14 delivery (about $110 USD). Expensive, or about right?

Thanks.

Re: PCX suddenly won't start

Posted: Wed May 24, 2023 7:45 pm
by Jge64
If you’re buying the yuasa battery, which is OEM, yes, it’s about 110 bucks, but there are many on Amazon that are half that, just measure your battery: length, width, and height, and find one on Amazon that is about the same. Except for sizing, 12 V batteries are 12 V batteries.

And from now on, if your bike is not gonna be used for more than three weeks, put a charger on it overnight.

Re: PCX suddenly won't start

Posted: Thu May 25, 2023 6:34 am
by PcxSomething
mymitzi wrote: Wed May 24, 2023 4:02 pm Put Baking soda on the liquid. If it's acid,it will bubble up.
Great tip, thanks!

Re: PCX suddenly won't start

Posted: Thu May 25, 2023 6:43 am
by PcxSomething
Jge64 wrote: Wed May 24, 2023 7:45 pm If you’re buying the yuasa battery, which is OEM, yes, it’s about 110 bucks, but there are many on Amazon that are half that, just measure your battery: length, width, and height, and find one on Amazon that is about the same. Except for sizing, 12 V batteries are 12 V batteries.

And from now on, if your bike is not gonna be used for more than three weeks, put a charger on it overnight.
Ah,great, that's great news on the money front.

Ok, about to order this. Looks the right dimensions and a makes the YUASA look a rip-off. The only difference I can see is that it's 6ah, where as the YUASA is 7. https://www.amazon.co.uk/My-Moto-Parts- ... B08C1GVDZH

Please give me a shout to stop me if I'm going wrong and I'll cancel!

Thanks

Re: PCX suddenly won't start

Posted: Thu May 25, 2023 10:53 am
by Jge64
Looks fine….get it……

Re: PCX suddenly won't start

Posted: Sun Jun 25, 2023 11:50 am
by pcx888
I switched to lipo battery. Never looked back.

Re: PCX suddenly won't start

Posted: Sun Jul 09, 2023 7:06 pm
by hop
Does that LIPO require a special charger?
pcx888 wrote: Sun Jun 25, 2023 11:50 am I switched to lipo battery. Never looked back.

Re: PCX suddenly won't start

Posted: Tue Jul 18, 2023 11:58 am
by pcx888
yes it does it requires a lipo charger I got the optimate lithum charger.

Re: PCX suddenly won't start

Posted: Tue Jul 18, 2023 1:21 pm
by Jge64
The lithium batteries that are being sold today can use a regular charger. However, you can’t use a charger that has a de- sulfation mode, but other than that, a standard trickle charger will work.

This info comes from Antigravity, that wrote about it on another board.

Re: PCX suddenly won't start

Posted: Sat Jul 29, 2023 8:49 am
by mymitzi
Hi Guys...."Another suddenly won't start". Was out for my usual 30 miler the other evening. As I was nearing home, noticed a slight flicker of
my instrument lights. Scooter still ran OK. Stopped at the Gas Station to fill up. Scooter wouldn't start. Pushed it home [conveniently near]
Turn key on, no sound from the fuel pump. Push starter, nothing at all. Wonder if You more knowledgeable riders can think of some thing
that would render both fuel pump and starter inoperative. I replaced the Battery [original] Checked all the fuses [OK] By the way......Horn
and lights all work fine. [Except headlight which only comes on after start] Appreciate your suggestions.

Re: PCX suddenly won't start

Posted: Sat Jul 29, 2023 9:50 am
by mymitzi
Forgot to mention........the check engine light..... doesn't come on at all.