If you still have any crimped on fuel hose clamps on the engine then they should be replace with screw type fuel hose clamps, not Jubilee clips. The crimped clips are notorious for leaking and should be replaced on any part of the M3W, there are some around the fuel filter and pump as well. If that turns out not to be the problem, check the fuel tanks out, particularly around the attachment brackets and the filler tube to RH tank weld.
