That's right it is the water trap.
Attachment 51098
As per the main topic. Correct me if I'm wrong, but you would get better fuel economy facing the head rearwards, simply due to less air being pushed in, therefore, the MAF sensor will lower the fuel mixture as well ? I dare say he may have also had a proportional power loss too (probably not noticeable).
There is also the "venturi" effect , which was talked about a few times, when it comes to facing the snorkel rearwards.
https://www.google.com.au/search?sou...fect%20snorkel