take off the tree/rods etc then the top to get at the innards & see if there's a bunch of crud (as said rebuild if it is that bad or just blast out the bowl with a can of brake kleen) as (if) needed. Wouldn't hurt to replace the needle/seat assys while you are in there with some good quality pieces. If TQ needles/seats are seperate (iirc they are) then twirl the tapered neoprene tip on the seats in between your thumb/forefinger to smooth them (that's my OCD talkin) and be sure to blast the seats. As said check your floates & a good procedure was posted above. Short version: replace the filter with a Wix/twirl the needles/inspect the bowl/check/reset the floates.