Downtown won't start

[ScooterWolf]

I need something cleared up, me being the OCD type: when you say the engine won't turn over that means to me when you push the start button all you get is silence, right?

The fact the brake light won't light tells me your brake switches are inoperative in both brake handles. They need to work or the starter won't spin. You can bypass them to prove whether this is the cause.

The spark plug would have nothing to do with this problem since assuming the starter won't spin the engine. I guess I was not the only one confused!

When I try to start the engine - ignition key turned to 'on' - dashboard lit up, no engine light coming on -I turn the kill switch on, hold in the brake and push the starter button. I hear the engine begin to rev up, but the engine does not fully turnover to be running. Just the sound of the engine trying to start up, but that's it.

Even if I give it a little gas it still won't fully come on.

* Battery seems to be fine.
* Fuse aren't blown

I last rode the bike about a month a go with no problems, but about two weeks after that I tried to start it again. When it failed I put it on a trickle charger. When the battery was fully charaged, despite that, it's been in the current state that I describe above.

- Wolf

[ScooterWolf]

I just put it back on the trickle charger as it occurred to me that the battery may be low again from all of the staring attempts I've tried. The charger's giving a red light to indicate a low charge, so hopefully I'll know in a few hours.

- Wolf

[Stig / Major Tom]

I just put it back on the trickle charger as it occurred to me that the battery may be low again from all of the staring attempts I've tried. The charger's giving a red light to indicate a low charge, so hopefully I'll know in a few hours.

- Wolf

How old is your battery?
If it is the original Kymco battery from 2013.....!

Stig

[CROSSBOLT]

When I try to start the engine - ignition key turned to 'on' - dashboard lit up, no engine light coming on -I turn the kill switch on, hold in the brake and push the starter button. I hear the engine begin to rev up, but the engine does not fully turnover to be running. Just the sound of the engine trying to start up, but that's it.

Even if I give it a little gas it still won't fully come on.

* Battery seems to be fine.
* Fuse aren't blown

I last rode the bike about a month a go with no problems, but about two weeks after that I tried to start it again. When it failed I put it on a trickle charger. When the battery was fully charaged, despite that, it's been in the current state that I describe above.

- Wolf

Okay, so the starter DOES turn the engine over...

When you had the spark plug out, did you lay it on the engine with the plug wire on the plug and spin the engine with the starter and SEE a spark?

[ScooterWolf]

Okay, so the starter DOES turn the engine over...

When you had the spark plug out, did you lay it on the engine with the plug wire on the plug and spin the engine with the starter and SEE a spark?

Thank you. I will try that next. The battery is still charging at the moment, so I’ll give it a shot in the morning.

- Wolf

[Ruffus]

NO brakelight ON, NO FIRING UP.
If you pull your brakelevers and ignition is on, there should be your brakelight lit....

-IF NOT, pull off this small cables from your brakelight switches and connect them by a short piece of wire or whatever metallic...
-ignition on, is your brakelight on?

-igntion on, brakelight on, push start button
Does is fire up now?

IF YES, your brakelight switches need to be renewd.
Hazard lights might be a different story...

[ScooterWolf]

Got her started!

With all of my thoughts about possible water in the gas tank (among other crazy theories) It occurred to me that there could be a vapor lock problem with the tank. Over the past few weeks the weather in our area has been up and down with warm mid 70F days followed by low 40 to upper 30s. I’ve never had a vapor lock problem before, but there’s always a first time. So I went out to my garage, and unlocked the gas cap.

Sure enough I could feel a gout of air being released. I tried to start it up and it sounded like it was really close to turning over. Pusher out of my garage I pushed up and down the lane behind my house and tried to start her up again, and yes - she turned over!

Somethings are still odd. The back brake control doesn’t activate the brake lights, but the front one does. Also, I have to hold in the front brake control while hitting the starter button to turn her on. Before I could do this while holding the back brake control and hitting the starter switch. This allowed me to easily give it gas if needed to start the engine. I just completed a 25 minute ride to see how everything is running. The bike felt amazing, no different than it felt before it was too cold to ride last earl December.

With it being starting now I can take her in for my annual Spring tune up and see if the control systems may have defaulted to a factory settling, or if there is a faulty wire or contact somewhere.

Anyway, who knew the bike just needed a good fart to get her started. Regardless, thank you everyone for your kind suggestions and advice.

- Wolf

[Ruffus]

@Wolf, your left brake-lever-switch needs to be checked or renewd.

[stuo]

I had the same problem with the DT300 I owned: both brake light/starter switches eventually stopped working due to excess current passing through their micro switch contacts, causing arcing, pitting and eventually failure to conduct electricity.

After you replace the burned out switch I recommend you replace the incandescent brake bulb with an LED, which will draw 80% less current and thereby not burn out those switches, which obviously are inadequate for the job. 

[ScooterWolf]

Good advice Stuo, and Ruffus. These will be the first points I will talk about when I take the bike in for her tune up.

- Wolf

[CROSSBOLT]

I had the same problem with the DT300 I owned: both brake light/starter switches eventually stopped working due to excess current passing through their micro switch contacts, causing arcing, pitting and eventually failure to conduct electricity.

After you replace the burned out switch I recommend you replace the incandescent brake bulb with an LED, which will draw 80% less current and thereby not burn out those switches, which obviously are inadequate for the job.

The truth be known, the proper design would have put those switches controlling a RELAY instead of a high current lamp filament! An LED replacement is anvexcellent suggestion.

Wolf, you have described a situation of vacuum operated fuel tank vent vave sticking. That "whoosh" was air entering the fuel tank. Because that valve is stuck shut. It sticking is intermittent. Happens on many modern brands annd is not model specific. Had it happen first on a Buddy 150, Yager 200i and two(2) DT300i.

My solution is to vent the gas cap. The valve is so buried on a DT300i that venting the cap is way easier. I made a post with pictures way back. The "Stall of Shame" was coined by the Buddy forum.

[Stig / Major Tom]

Not a major point....but EFI starts are best accomplished by never touching the throttle.
Glad it's running 🏃
Stig