No matter how hard and carefully you clean a vintage fuel tank, some crud will still continue to come out. Some is coming from the fuel itself, some, like in my case initially, was just 20 years worth of deposits from sitting in a barn for too long.
Long story short, I have decided to put a massive, non fuel pump, fuel filter before the carbs, especially since my vintage Mikuni do not have filters. Wow, I cannot believe I just write that, who makes carburetors without filters, arg!
So I purchased a very fine filter (see Wix 33001 ) and a couple of T couplings and put it in the middle of the flow coming from either the main line or the reserve.
The trick is to make sure it stays above the float bowl of the carburetors or, Archimedes will tell you, you are not going to get any fuel. I achieved this by making it rest atop the air filters and carefully routing the fuel lines. Done. It works like a charm and my carbs no longer require cleaning every 5 minutes ;-)
Oh and yes, the dark stuff you see it is crud, the paper filter is actually white. Sold yet?
