B737CL NP Engine Start Procedure
 

Hi all. I would like your help. After the last revision of FCOM (June2015) in the normal procedures, in the after start it has been added the following phrase.
"If after engine start, the ground crew reports a fuel leak from an engine drain continue to run the engine at idle up to 5 minutes. ..."
Does anyone can help me identifying the position of engine drains, and where this possible leaks can be located?

The pipe that is connected to the pylon, where the engines is attached.

On the walk around some times you can see it leaking, if smell it, and it smells of nothing then its water, if it does, you got a fuel leak in the pylon.

The drain mast comes out the bottom of the engine nacelle - right below the lower bifurcation. The drain mast actually is several different drains - one can determine what's leaking by which drain pipe the fluid is coming out of.
After engine start - especially if it's really cold (sub zero F), some of the seals don't seal well until they start to warm up. Small amounts of leakage (measured in "drips per minute") are allowed during this warmup period - but the leakage should stop when up to temperature.

Thank you very much for your responses

There is no drain mast, its just a hole/scupper in the bottom aft end of the right fan cowl.