posted 05-04-2002 12:04 AM ET (US)
Last spring I renovated the fuel system on my boat. All the lines I removed were grade A1.I ended up using grade A1 hose from the tank to the filters. This got the lines above deck and close to the motor well.
From the filters to the engine I used grade B2, as this was more flexible and cheaper. I also figured I could replace it easily if it proved to have poor life.
In researching about the legally required grade of lines I don't recall finding much about outboards. I believe I got to a dead end when I needed the ABYC recommendations. They are not on-line. You have to buy them for considerable money (like $200). That put and end to my curiousity, and I used the hoses I described above.
If you read the USCG regs, they seem to point to A1 or A2 hose for fuel lines. I'll have to go back and look at this. I was going to put an article together on this topic, but I ran into another wall when my primer bulbs were such a problem. (This got solved this spring with the hint to point the arrow upward when priming.)