This is an OEM replacement part and is sold individually.
Its purpose is to filter out dust and debris from contaminating the carburetor and engine.

When replacing the filter you can open the package in comes in and put a bit of two cycle oil in the bag and let it absorb into the filter. Then remove it from the bag and squeeze it with a paper towel to remove the excess oil.
This will aid the filter in filtering out the unwantables.

The 791-682039 Fuel Filter and Line, filters the fuel in the tank as it is forced into the carburetor up by means of the primer bulb.

To install.
Remove retainer ring from fuel line.
Insert fuel line thru gas cap opening.
Thread fuel line thru hole in bottom of the fuel tank.
Pull fuel line thru to firmly seat against inside tank wall.
Put retainer ring on fuel line,hold line and press ring firmly against the out side of the fuel tank wall.
Then attach fuel line to correct line on the carburetor.

The filter will at sometime get clogged with dirt and debris that has collected in the fuel tank, and will have to be replaced.

The primer hose is inserted into the fuel tank then connected to the Primer.
By pressing on the primmer a few times this assembly fills the carburetor with fuel.
When the carburetor has enough fuel in it, the excess fuel is forced back into the the tank through the fuel return line.

After time the primer hose will become brittle and crack and have to be replaced.
The primer will also lose its elasticity, and may also crack and not be able to suck up the fuel into the carburetor.
And will have to be replaced.

The purpose of the 791-181086 Fuel Return Tube is to return the excess fuel back into the fuel tank, after the primer bulb has been pressed and has primed the carburetor to start.

After time the Fuel Return Line will become brittle and crack and will need to be replaced.

Genuine Manufacturer Approved Carriage Bolt is a standard part that fits a variety of products. This part is sold individually and the Nut is not included. The square area under the head is designed to fit into a square hole in the work piece it measures 5/16-18 x .75. It is this square hole that restrains the bolt and keeps it from turning when the nut is tightened.

This is a Manufacturer Approved replacement nut for lawn and garden equipment. This item is Metal an is Sold Individually. A lock nut is a type of nut that resists loosening when properly threaded onto a bolt.