170i Engine Shut Off

[mukaiboston]

I'm sorry if what I am about to ask is common knowledge, but I'm not really up-to-date on fuel injection terminology so I'm having a lot of trouble searching for this.

I recently got a used 2013 Buddy 170i with 5k miles on it. Three times so far, the engine has died on me after I pulled the throttle and then suddenly hit the brakes.

It happened this afternoon. I was pulling out of a parallel parking spot so I pulled the throttle kind of hard to pull out enough to get a good view of the street. When I realized there was a car coming toward me, I braked suddenly and the rpms dropped causing the engine to die.

The time before that, I also pulled the throttle really hard to pull out of a parallel parking spot. The spot was a few feet from a red traffic light, so I braked as soon as I pulled out of the space and the engine died.

Both of these times, the engine was cold and I revved the engine and then braked suddenly. (I know it's not really great to drive like that, but this is a city so it happens).

This is my first EFI scooter so I'm not too familiar with how fuel is supposed to get delivered but I did some research and it looks like when the scooter is coasting, the forward momentum keeps the engine turning. Once the scooter slows considerably (engine braking?), the fuel injectors kick in to keep the engine idling. In the two examples above, it appears the scooter gets confused and doesn't inject fuel to the engine when the rpms drop all of a sudden. So instead of automatically going to idle, the engine just stops receiving gas and can't run.

Note that this only is happening right when I start the scooter. I drive in stop and go traffic for at least half my trip after that and it's fine.

Is this a normal issue and is there anything I can do about it? Or do I just need to start out slower? I've been reading some posts about getting the ECU updated and stuff.