I have a 2000 mxz 700 and it seems to be losing fuel overnight and it doesn't seem to be leaving any fuel on the bottom of the sled. I have placed papertowels under the lines and around the pump and the next day it is dry. I don't know if it is a worn fuel pump seal or a pin hole in the line to the crankcase. If you can help me with any ideas it would be a big help to a problem I have been having.

Sorry I forgot to say that The lines to the carbs are what drains down the tank doesn't change in level thanks.

check your float height in the carbs sometimes if the floats are too high they will leave the needle open and let fuel leak into the crankcase. thats really the only thing i can think of, anyone else?

your needle and seat has something (debris) in it and is not closing, float bowls are draining into the engine and airbox. Try to fix right away... Turn the fuel line off over night for now.