fuel pressure on 265
i have a john deere model 265 mower, and i went out yesterday to get it ready for the season. i was not able to get it started without using a little fuel poured into the carburetor. even after that, it would not stay running. after doing this routine for about 15 minutes, it did start and stay running, but i could not move the throttle up without it knocking off. i looked at the fuel filter, and it was not full of fuel. i do not know if the filter is only supposed to be 1/3 full or if it is supposed to be full all the way. does anyone have any ideas as to what i could check to see if it is getting the proper amount of fuel in the carb? or what i could check to see if the fuel pressure is good enough? i don't know what it could be that is preventing the engine from normal running conditions. any ideas are greatly appreciated, thank you.