Spark Plug

Take the whole air cleaner off. The take off the fuel lines off the carb. Take the screws out and remove the old carb. and put the new one on and tighten the screws. Put the fuel lines on and the air cleaner. Take out the spark plug and put in the new one and gap it at 0.025

1. Removing air filter cover and air filter
2. Removing 2 screws holding filter base and carburetor
3. Removing gas lines and removing accelerator cable
4. Connecting gas lines and accelerator cable
5. Screwing back new carburetor and filter base
6. Installing new air filter and cover
7. Replacing spark plug
8. Starting it and checking that everything is ok.
Done!

1. Removed carburetor and spark plug
2. Installed new carburetor and plug.
3. Pulled rope and started instantly.
Changed spark plug as part of preventive maintenance. Old plug was still good. Carburetor was the issue. I have a TroyBilt TB575EC trimmer 4cycle and it looks like now I'll have it for another 10yrs.

1. Removed the cover to the air filter
2. Removed the 3 screws holding on the outer cover
3. Loosened the bottom two screws on the lower outer cover.
4. Slide the bottom cover back, and pulled the gas tank out.
5. Removed the two screws behind the air filter, pulled them out and slid the carburetor up.
6. Hooked the new gas tank line to the new carburetor. Ran the line from the carburetor to the primer. Then ran the primer overflow line back to the gas tank.
7. I slid the carburetor in replaced the two screws, then slid the new gas tank in. Tightened the bottom two screws that were just loosened to hold the gas tank in place. Replaced the top cover put the final three screws back in. Then changed the spark plug. It fired up on the second or third pull and ran better than when I purchased it new.

The choke was not closing tight, making it hard to start.
Replace air cleaner/choke and spark plug.
Now it start on first or second pull every time

1. Removed the shroud per manual.
2. Unscrewed the valve cover and the adjusted valves.
3. Replaced the cover with the new gasket.
4. Replaced the spark plug with the new one using a spark plug wrench.
5. Put all shrouding back on and the tested the trimmer.

1. Removed six screws holding top plate
2. Pulled plug wire and removed old spark plug, gapped me one, and installed new one (see owners manual)
3. Removed old fuel tank and rubber mounts. Be sure to note there were two fuels lines, so proper orientation is critical.
4. Install rubber mounts and tank, then cut fuel lines to length and install those.
5. Reinstall top plate with the six screws
6. Fuel filter change out per owners manual was a breeze.
7. All done.

1. Removed old fuel lines, filter, primer bulb. Lines and bulb cracked apart due to age.
2. Replaced fuel lines, filter and primer bulb with new parts. I had to remove the preassembled fuel filter from the fuel line so I could feed the new fuel line into the tank from the outside. Once the line reached the opening for gas I reattached the fuel filter to the line. I have no idea how the fuel line can be fed through the fuel line hole at the top of the tank from the inside of the tank on my Ryobi 990r trimmer.
3. Removed old spark plug and replaced with a new one.
4. Removed carburetor, took it apart and cleaned it with carburetor cleaner, replaced all carburetor gaskets with new gaskets. Take pictures as carburetor is disassembled to make gasket placement and reassembly easier when you put it back. Also note the hole that the throttle cable is attached to on the throttle link to before you take it off the throttle link.
5. Reassembled outer plastic covers on trimmer with new air filter.
6. Engine starts right up now.

Removed old fuel tank, air filter housing and carburetor by removing 4 screws
Installed new fuel tank, carb, air filter housing
Cut fuel lines to correct length
Pressed fuel lines onto connectors
Removed spark plug with socket wrench and replaced new one
Filled with gas, pumped primer bulb 6 times
Started on fourth pull and ran like a champ

Removed old housing & small screw on the bottom.
Replaced with new