Sinnis apache 125cc not starting

[justpoc]

Hi all, decided to turn for help to forum, probably missing something obvious and hopeing i can be pushed towards right direction.
Sooo, tried to help out a fellow rider with jump starting the bike with no luck. Only to notice a day later that my bike is not starting.
Tried jump starting from a car with no luck. Bump start seemed to work only once (did not think of it much and was happy it started once). Decided to change battery as it was already quite old and thought I probably killed it. Bike started seemed to run nicely, after a mile or so and few misfires at the end it just died on the road. Managed to start a few more times, each time just for a few meters of ride until it completely switched off.
As I was about to start looking for issues, decided to fix few small issues and do a part of service as it was about time anyway.
New spark plug, generates healthy spark.
New carburettor (changed it as old one had an issue affecting throttle and was just in a queue for a repair anyway). Checked the fuel and it comes clear, even drained and replaced with a new as bike stood for few weeks without moving. Carburettor should be operating as it is supposed to I guess.
New starter motor (accidentally damaged it when disconnected to clean it. Located in front of engine and was covered in thick dirt.. please do not ask why did I bother at all... )
Checked compression and according to manual all fine.[/list]
That leaves timing, I guess. As it happened after jump starting, my best guess is of course electrical part... The only part I can think off is CDI unit malfunctioning. Now don't want to start changing components when no idea what is wrong nor digging deeper into potential mechanical faults as it just does not make sense.
The question I have is whether it is somehow possible to check if CDI unit is performing as it is supposed to or potentially I should be investigating something else too?
Sorry for the very long text but wanted to paint the situation how I experienced and understand it. Silly thing to play with jump starting when not fully aware of correct procedures... A lesson to learn.

[Easy-X]

You say the battery is old. Why not start there and replace it?
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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

[justpoc]

[Easy-X]

[bikenut]

As above, also research red neon plug caps that flash as they pass thru HT, the spark.

Cheap effective hassle free but you may have to make an adaptor so it fits hassle free between plug in engine and existing plug cap.

When it dies does it stop flashing ?

If/when it misfires does it stop flashing in time with the misfire.

With a good clean correctly gapped plug and neon fitted and engine idling, does the flashing go brighter with revs ?

It's a bit of cheap test kit, not a real cool flashing but of bling for your bike.

You should be able to see the flashes if you are riding bike, particularly at night.

An other low tech test, with front of bike by a wall, engine idling and headlights on, do the headlight grow brighter if you rev engine to say 4 to 5 k revs ? Yes ? Good. No, bad. !

What year your Sinnis ? Post wiring diagram so we can see...

Is it edit or carb version, and goto sinnismotorcycles.co.uk or what ever it is, for the parts diagrams, exact model,vso we know what's on it...etc.
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nuts about bikes

[justpoc]

It is 2015 Sinnis Apache 125 Non EFI (QM125GY-2B).
Problem is that it does not start now so cannot make any tests on running engine.
I will try to get on testing the electrical parts this weekend. Wiring diagram attached (uploading from mobile, if quality is bad I'll update on PC when have a chance), from repair manual.

[WD Forte]

that diagram suggests the side stand switch dumps the pulse signals to ground to stop the motor
( as does the stop and ignition switch, test those too)
try disconnecting it as they been known to play up

https://www.bikechatforums.com/download.php?id=104375
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bikers smell of wee

[bikenut]

The power of a few lines in a bit of paper eh !

Now you have your "road map" for the exact wiring on your bike, you can use your dmm to good effect confident that you now have info to act on.

You have a dmm and red neon plug cap now, to relatively cheap, effective and sensible bits of kit that will pay for them selves the first time you use them.

These bits of kit will come in handy for years to come, so look after them.

Study your diagram and learn certain circuits, the first being the ignition and starter motor circuits.

Take you time, be methodical, one thing at a time and don't flit here and there. Record what you have checked and results.

Remember the battery should be fully charged and is your reference and starting point.

Don't forget the earth circuit.

Enjoy, give feedback.

Others can also learn from your experience.
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nuts about bikes

[bikenut]

Note

I saw a box in the wiring diagram marked ECU.

Like you, an ECU will not like a spike up its bum !

So avouid electrical spikes which can be caused by hot-wiring, using jump leads.

This you have already done.

Always make sure the main ignition switch is OFF when disconnecting your battery and OFF when connecting your battery.

The wires in the diagram are connected with a Dot, just like a roundabout, and wires which cross but not connected have a hump back bridge, or leap over the unconnected wire. 😎

Hands up those of you that did not realise that.
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nuts about bikes

[wr6133]

[bikenut]

They are not the be all and end all, and could be a problem in a deeply recessed plug, and on a bike with a fairing, but they work for me.

An adapter would have to be made for a deeply recessed plug, L shaped possibly, and an adapter made so it fits inline and easily using the bikes original plug cap, but that's down to the application ( cx500, kwak gpz750, the one that the engine will run with the cam cover off ).

They work for me and have done for years and years.

Wasted spark ?

When the misfire happens and no flash, then no HT.

Yes, is it fuel, is it a coil breaking down under load, going up hill ?

A visual indication would help, unless you have lots of hair.

You could always stick your finger in the plug cap, bit difficult when riding I think.

Do you check your mirror and is your fairing welded on ?

You will not know of there usefullness untill you try them, they dont Cost a fortune.

Dim flash at cranking, brighter flash with revs...dim flash when at idle, intermittent flash when intermitant misfire starts at 4 to 5 k revs, is it fuel ?

Of course there may be a fuel problem as well....

But you need one really long lead for a scope, unless you have one of those battery powered ones, or one in a laptop....there's always your finger up the plug cap 🤩🤩
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nuts about bikes

[bikenut]

Alternatively a neon timing light light with leads could be utilised..... 😁

Or even the 12v power timing lights, tape the trigger, clip on sensor lead, but the light is quite bright so don't have it shining in your eyes whilst riding your bike, particularly at night.

Of course the plug may need a shave, those dam cats again.
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nuts about bikes