This mower has a plastic, spring loaded cover that closes over the exit for the grass clippings at the rear of the mower, and acts as a cover when the grass catcher is in place to prevent clipping from covering the operator. It's broken off and need to be replaced. I don't see any replacement part available as I look around on line. Any ideas?

a buddy asked me to look at his husqvarna 323 trimmer. he said it would start and quickly die. he dropped it off with a rebuild carb kit, but when we tried to pull it so i could get an idea of what was happening, it wouldnt pull. it turns out the flywheel was loose. after i tightened it and put back together with new carb guts, it pulled normally, but it will not even attempt to turn over! I have spark and compression, but not sure about fuel. the primer bulb pulls fuel through, but the cylinder doesnt seem to be getting any fuel...weird. i pulled the carb apart and cleaned with cleaner and blew out ports. all seems clear. any ideas? Quick recap: got spark, compression, sprayed starter fluid into cylinder and it does not even try to turn over cleaned carb, rebuilt