View Full Version : White PVC

07-13-2005, 04:13 PM
Question, I have a 02 Outback and bought it used this last spring. Anyway I was adjusting the shaft packing yesterday and noticed there is a large PVC tube that is in between the mufflers.

Does anyone know what in the heck it is in there for. It has a tie around one of the exhuast.

Doug, t-town

07-17-2005, 04:37 AM
Its an air conduit. Should have flexible plastic conduits attached, in turn attached to an inline blower fan and to an air discharge grate on the back of the boat.

I think different configurations are used on different boats. All inboards and inboard outboards require a ventillation scheme under the floor.

You should also have ducts in the vicinity of the windshield that scoop air and duct it down under the floor near the midsection of the boat. These ducts dead-end near the midsection.

At speed, the scoops maintain a flow of purge air through the bilge.

At low speed or at rest, especially for a few minutes before start-up, the blower provides the purge.

The hard duct you see is more robust than the flexible stuff, so they used it near the mufflers.

My 99 Ouback has a problem. Besides not being hooked-up at the factory, which was serious enough, the flexible ductwork has become brittle cracked, broken, disconnected, etc. So I need to replace the flex. Will probably substitute and use hard PVC wherever possible. Gotta have ventilation. Otherwise, the day that it develops a little drip of a fuel leak could be the last.

07-18-2005, 09:35 AM

thank you. finally someone was able to tell me what it was for.

makes sense.

hope everyone is having a safe boating season.