Yesterday, after riding about 10 minute, my motorcycle engine stop when coming to a traffic light. It can start again straight away but I need to keep the throttle going, if not the rpm will drop and the engine stop again. It is strange that it can start straight away easily, show no sign of weak battery.

When I reach home, I let the bike rest for a day and I check the battery voltage. It is 12.5v when the bike is off and 14.15v when the engine is running around 2000rpm.

Is there anything I can check before I bring it in to Harley? My motorcycle is a 2014 Dyna Street Bob with security system.

 

Check your battery wires, both at the battery and ground connection.
Try cleaning your IAC.

 

To check what is IAC? The battery is stock condition, well take care of. Both + and - are clean and secure

 

Here's a video:
Just Google it and you'll find lots of info.

 

before I traded it ...my 07 SG did the same thing...traced it back to the fuel system from Fuel motto....never did get the % right

 

Real high odds that this is the problem. Both mine and my Sons have done the same thing and this cured them both.

 

Thank you everyone for the information. I open up the air cleaner cover, remove the filter and clean the hole on the top. And it work well now. Maybe Harley Davidson can write this cleaning procedure in the manual for every 5000 mile service.

When I open up the air cleaner cover, I do noticed that inside is quite dirty. Maybe this is the issue that cause the engine stop when I close the throttle. Recently, I wash the motorcycle more regularly. The air cleaner has a big hole opening from the front, washing or raining and the water may go in, not sure the water evaporate inside the air cleaner cause some issue to it too...

I understand that when the throttle is close, the hole outside the butterfly valve is for the air from outside to enter into the inside of the carburetor to combine with the gas to continue combustion to let the engine continue running. So if the hole is dirty and block the air, there is no air from outside to pust the push into the carburetor. But there is one thing I don't understand. When the engine stop after I close the throttle, I can still start it straight away. Isn't the butterfly valve is already close and the hole is block from air to enter...?

 

First of all, you don't have a carb. What you're looking at is the intake for the fuel injection. The butterfly/throttle plate does not close all the way when you let off the throttle, there is still a gap that can be adjusted if necessary when tuning the bike. Do not try to adjust it, it seems to be working properly.
Good job getting it cleaned, now just ride it.