2012 dowtown starting issue

[Volcabar]

On thursday I filled it up, friday morning doesnt want to start, I come back from work, it starts.
Yesterday it started right away and I rode it to and from work, 55 km both ways.
Today it didnt want to start.
So what could be wrong?

[TBR125]

To better understand the problem, when you say it "doesn't want to start" is the engine turning over but not catching, or is the starter not operating. If it is the latter then the issue is an electrical problem which someone else will have to address.

If the engine will not catch then the basics to check would be fuel, spark, air probably in that order. To check for fuel pull the spark plug and see if the end is damp, for spark press the starter switch while watching the spark plug for an arc (a dark background might help), and for air make sure the filter is reasonably clean.

Hope that helps, good luck with diagnostics. 

[Volcabar]

Yea, its turning over, but doesnt start it.

[TBR125]

Okay. Fuel, spark, air applies then.

[Volcabar]

Started it again after work, rode  a few km, parked it, shut down, turn the key on, showing engine light code 33.

[TBR125]

I have not worked with modern bikes. Sorry I can't help with engine codes.

[rdhood]

I would check all connections to the sensors and throttle body.

[CROSSBOLT]

Code 33 injector fault. Not necessarily! The ECM is activating the injector by providing a ground to one side of the injector coil. The other side is powered by the fuel pump relay. So before you go down the road the service manual sends you do THIS: LISTEN! When you turn the key on and the tach and speedo do their full scale dance up and back to zero. You should also hear the fuel pump running. I will bet you do when it starts and you don't hear it when it does not start. That means your fuel pump relay is faulty, not the injector!

All the relays in the DT300i are the same part and part number. So if the LISTEN test says "relay" use the hi-beam relay as a replacement while you wait for the part to arrive. Kymco wants 28 bucks US for the relay and I got 5 of them from Amazon for 8 bucks. Single pole, single throw (SPST) relay, automotive.

How do I know this? My 2013 DT300i did the same thing recently!

[Volcabar]

Code 33 injector fault. Not necessarily! The ECM is activating the injector by providing a ground to one side of the injector coil. The other side is powered by the fuel pump relay. So before you go down the road the service manual sends you do THIS: LISTEN! When you turn the key on and the tach and speedo do their full scale dance up and back to zero. You should also hear the fuel pump running. I will bet you do when it starts and you don't hear it when it does not start.

What do you mean with this?
I can hear the fuel pump.

[Volcabar]

Also there is one hose going from where the air filter is that is not connected to anything, what is that for?

The furthest one on the picture.

https://ibb.co/Njvrkdb

[TBR125]

Looks like a breather hose.

[CROSSBOLT]

What do you mean with this?
I can hear the fuel pump.

The fuel pump is heard EVERY time? Even when it won't start?

The furthest hose, that the one that looks kind of tan? If that is the one you are indicating, it is supposed to have a black plug in the end of it. Very hard to see. Must lay on your back and look up. The slang name for it is the "Puke tube." Must be drained periodically.

[TBR125]

I learned that a couple weeks ago. My bikes manual doesn't tell about it and the oil/fuel backed up into the air intake. It made a mess of the carb.

[CROSSBOLT]

That Puke Tube slop will stop an engine! Or at least give it aches and pains! Stuff generally stinks like stale fuel and has the consistency of soy sauce.

[TBR125]

That is why it no longer vents to the air intake. I have all vent lines sealed into the lid of a small container that I can pull the bottom off and dump.