YBR125 Flashing engine light but not an error code, no start

[whyber]

Ello. A while back you guys were helping me with my YBR125 charging issues that turned out to be a burned out stator coil.

Thread here:
https://www.bikechatforums.com/viewtopic.php?t=335579

I changed the stator out. This fixed the charging issue - now get 14v with 5k revs which I believe is about right. Over 13v at idle.

Previous to all this, the bike had always started on the button no problem. After doing the stator change, it has had starting issues, cranking over (fine) lots before starting. Interestingly, kicking it with the kickstarter had much more success.

Last night, after doing some running about with several starts, I went to start it again and it didn't want to fire.

Pump audibly primes. Engine light comes on for 3 secs as expected while pump primes. When going for ignition you can hear pump working. It might have got louder recently but it might just be my imagination.

But now, when it doesn't want to start, the engine light is flashing while the button is held down. It doesn't flash a sequence to indicate a code. Only flashes while starter motor is spinning.

Haynes manual says it does this to "indicate a bad problem that stops the engine running" or somesuch.

But the thing will run happily, it doesn't always do this. It's intermittent. So I don't think my electronics are fried or anything. But it only has just started doing the flashy light thing after a week or so of poor starting, but running.

When I put the stator on I had trouble with the connector that goes up to the neutral switch. Couldn't get it to fit well at the wiring loom connection, that cylindrical type connector plug. I've basically mangled that on, but I think it has a connection OK.

Other known issues the bike has:

It's blowing headlight bulbs. I've done two since the stator trouble started. That might just be because I've been stupid and handled them with bare skin. I have to buy another to test again. But bike has a new regulator (put it on before I diagnosed the stator burn out), the voltage to the battery when running is OK, so I don't think it's that.

The ignition barrel connection is a bit poor. I have to fiddle with the key a little to make a connection so bike lights up. This is never a problem, just a thing.

Any thoughts gents? I know that's not much to go on. On the one hand, I'm hoping it's a bad connection thing or something. On the other hand, I don't know how I'm going to find it. I'm rubbish at electrics.
____________________
Hot and tired

[Nobby the Bastard]

Bad earth.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Ayrton]

[whyber]

I probably should have said in all this that the bike is an '09 with 24k on it.

I've got my Haynes and am looking over the wiring diagram at the grounds.

I'll check the neutral switch ground because that seem to be linked to the alternator that I;ve changed and crank shaft position sensor, which would be bad if that wunt right, obviously.

I don't think I need worry about other starter safety circuit grounds because the bike is cranking - if they weren't working properly, I'd have no starter motor action, right?

So ECU ground, ignition coil ground, reg/rec ground, fuel pump and sensor.

After that it's continuity tests and voltage checks on everything. Sounds like a right ball ache.

I'd better check the plugs and change that air filter that I've had for ages first . Though I'd be getting an error code on intake air pressure if it was that, right?

I wonder how long it would take to just swap out the whole loom on this bike....
____________________
Hot and tired

[Easy-X]

[whyber]

Good point.

Here's wiring diagram if it helps anyone:
____________________
Hot and tired

[whyber]

It occurs to me that I could have installed the CKP sensor that sits next to the stator a bit wonky or something (don;t see how but I spose I better check it), or maybe the connection wiring isn't good. Not enough to trip an error code but enough to make things a bit crap.

But I'd imagine if that sensor wasn't working properly the bike would run badly all over, not just have starting issues.
____________________
Hot and tired

[WD Forte]

remove starter and service it
____________________
bikers smell of wee

[Easy-X]

The clutch and side stand switches feed into the ECU. Most likely that means safety = fuel injector cut if that's any help.
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[whyber]

[F18]