so you have not had a problem with hot exhaust fumes and the rubber neoprene tubing? is it the same as the black fuel line you can get in (insert mega marine retailer name here)?
and is your tubing hooked up to a thru-hull on the transom? pretty high up, right?
i am starting to consider a similar system.
my current system is a pair of small copper tubings bent to point out one of the ventilation cowlings. not ideal because they sometimes don't reach and sometimes fall out, filling the laz. with fumes.
not ideal at all.