Ninja 250R Carb Drain won't stop - a problem?

[Jonnie]

I'm asking this on behalf of a friend who owns a suspect 2009 Ninja 250R. He's had issues since the day he bought the bike and was hoping a carb drain would do the trick. His bike has a pretty rough idling sound and will stall when revving (cold start).

Having drained my own carbs myself, I decided to assist him. We had the petcock set to ON, and a tube under the drain nozzle. After loosening one of the drain screws, the flood came. While my carbs drained less than a 1/4 of a pop can, his carbs kept draining and draining and draining. We filled close to a beer bottle, when I realized something was wrong and I stopped the drain.

My question is, a carb drain should not produce that much fuel correct? Do you think there may be an issue with his petcock or carb? It seemed like the ON position didn't stop the fuel tank from supplying more fuel to the carb. Please advise! Thanks!

 

[S500K]

Petcock is the issue I believe.

Not 100% sure but just saw a few posts where they say - Turn petcock to off so when you start draining, you are only draining what is in the carb and the fuel system is cut off.

*Should be in the manual.....

most have a screw on the bottom of the carb,,, most times you shut gas off while bike is running and let it run dry

Generally, there is a drain valve on the bottom of the carb bowl, but if not, turn off the fuel, and run the engine until it stalls.

Shut the gas off and unscrew the screw. Best to catch it with a tube into a can or use a small tub to keep the bike clean.

 

[Jonnie]

It seems the 2008+ Ninja 250Rs only have an ON and PRI positions. I re-consulted the manual and ON is correct setting. PRI will just drain everything outright.

edit: Could it also be a vacuum hose problem?