Hi, How often do you check your gas tank plumbing and tygon fuel lines? I assembled my tank last fall with tygon tubing and flew the airplane about 5 times. Now I 'm getting ready to fly the plane for the first time this season and was wondering if I should replace the tygon with new. It is a slight pain to remove everything to service the tank but I would kick myself if I developed fuel delivery problems. What do you guys do? Also I have some Aerotrend gas tubing that has a larger inside diameter than the tygon. Is the Aerotrend less likely to get brittle and stiff?

I just replaced all of my yellow line with the blue Aerotrend. If you search, you'll find a thread from about a month ago on gas lines. It was a good one too.
My yellow line got hard enough that the clunk wouldn't make it to the bottom of the tank when the plane was inverted.
Scary[X(]

Anyway, it's time to replace any line when it's stiff enough to act like I described above_bob

Well I pulled the tank and opened it up and the tygon tubing was in perfect shape. I replaced it for good measure with the blue Aerotrend. So I guess the tygon will last for at least 6 months. I could have easily used it for this season but at least I have peace of mind.

I use neoprene (Dubro #199). It is said to be softer than tygon and last longer. It's my first year of flying petrol engines, so I can't say anything about how long it will last.

For the record, not all yellow line is Tygon. Tygon is marked in a certain way. ( I'll have to find that thread )

It's not that Tygon isn't a good product, it's just that there's alot of yellow line out there that isn't what we think it is.