I've had a 1997 670 summit and now I have a 97 mxz 670 and they both flood out when I either idle pointing downhill or when I shut the nengine off pointing downhill, I have to move the sled to a level spot, turn off the fuel, pull the rope until it clears the fuel and starts then turn the fuel back on! any suggestions?

If you are running the carbs on "shorty" intake boots, you need to lower the float level 2 mm. If not, check your float levels and replace the needles and seats. Another thing to verify is the fuel reservoir vent. If it is kinked or restricted, pressure will overcome the float needles on inclines.
MXZ Float level should be 18.1mm; Summit VM 38 - 40 should be 19.6mm
(measured from the float bowl gasket flange to the float levers)

yep, i had to shut my fuel off evey time i stopped, then i cleanednedle &seats out & lo& behold was i chunk of @&%!! in there holdng open the needle. might want to check that first imo....
d