If I am not mistaken, the mower is a Black Max and the engine is a Honda. If that is the case, this is the mower that Sams Club and Maybe Walmart sell. I am not sure if you have access to the manual, but based off of just your model number I am not sure if there is anything that you will be able to find on the web. You might want to try two things: walk into your local Sam's club and look for a more current model of Black Max mower and copy down any contact information that you can from the box which might point you in the direction of the actual mower manufacturer. You second option would be to call the Sam's Club 1800 number because they will likely have a number that they can give you to direct you towards getting the information that you are looking for.
Unfortunately, it might be that you will not be able to locate or even purchase the discharge chute. You could also try many of the small equipment parts websites such as partstree or boatsnet or whatever and poke around on those sites searching specifically for Black Max. Heck, a discharge chute from a newer mower made by them might even fit; deck designs among these cheaper mowers are less likely to change as often over time.
