.
My only explanation is that it got a good gulp of 98 and loved it
That's ridiculous and as likely to happen as peeing in the toilet and not having it mix with the toilet water.
no air leaks, tried the old d40 around the base o the manifold, no change.
that was pretty much a waste of time cuz wd40 is nearly useless for finding leaks . use flammable brake cleaner with the long nozzle and spray it GENTLY so it doesn't waft into the carb throat giving you a false reading.
tried the mixture screws. no change.
sounds like your carburetor is dirty or the power valve might be leaking a little or the throttle is open too far at idle.
set the gas level so it is around 4 mm below the inspection screw hole at idle . if it has a clear window, set it so the level is 1/4 up the window.
remove the idle mix screws and spray flammable brake cleaner in the holes with the long nozzle for 3 seconds.
reinstall the screws set 3/4 turn out from full in.
place the long nozzle directly against the holes in the top of the carb and spray each one. watch your eyes and paint.
remove one of the bottom float bowl screws and drain the gas into a paint can lid in case there is water in it. put a wad of paper towels below it first.
make sure fuel comes out of both squirters as soon as you barely open the throttle by hand.
make sure there is zero vacuum to your distributor at idle.
make sure the timing returns to the same place every time at idle.
