How to Clean a V-Star Carburetorby Richard Rowe
Officially known as the DragStar overseas and the V-Star in North America, Yamaha's modern muscle bike hit a sweet spot among cruiser bike enthusiasts. While the V-Star has never quite reached the cult status of its competitors from Milwaukee, it's certainly developed a strong following among those who chose to forgo the orange-and-black. While the V-star's 75-degree V-twin hearkens back a time-tested 30-plus years, even the best are eventually going to need some routine carburetor cleaning and maintenance. No big deal if you've ever seen the inside of a carb, and still doable if you haven't.
Remove the seat from your bike and close the fuel petcock valve. Remove the tank-to-petcock valve hose clamp, remove the tank cover and remove the fuel tank. Remove the airbox and air ducting to expose the carburetor. Label and disconnect all the hoses, or take a few pictures in the process of disassembly so you can get things back where they belong later. Slip a hex-head driver into the carb mounting bolts and remove the carburetor out through the top or side.
Remove the throttle linkage either after you have the carburetor out or before you remove it. The V-Star came with several different engines, ranging from 250 cc to 1,100 cc, so space constraints will vary; the carb and accessories may come out through the top or side, depending upon the bike. Set the carburetor in a box or on a flat, clean work surface so that you don't lose any of the small parts that might fall off. Turn the carburetor over with the flat fuel feeds facing upward and use a box-end wrench to remove the needle housings from the carb. Look inside the holes for junk in the carburetor.
Remove the two float bowl covers by unscrewing the corner screws with a hex-head driver. Be very careful not to strip the screw heads. Wiggle the float bowl covers loose and remove them. Remove the drain screws from the bosses on the float bowl covers. You've now exposed the main float.
Pull the float pivot pin out and gently pull the float out of the carb. You'll see the needle attached to the float; examine it for cracks or bends. Identify the jets; they're in the recess where the float needle went in. Unscrew the jets with a screwdriver. You'll see the holes around the bottom cylinder of the jet. Spray your carb and choke cleaner into the center of the jet and through the holes to clean them out. Set the jet aside. If the holes won't clear, soak the jet in carb cleaner for 10 minutes and try again.
Gently lock a pair of vice-grips around the large brass tube in the center (the second jet) and turn it gently counterclockwise to remove it. Blow some carb cleaner through it or soak it as you did the first. Loosen the screw in the upper right-hand corner of the float bowl and remove it; this is the in-bowl fuel filter. Clean or replace as necessary. Repeat with the brass screw in the top of the bowl to expose the needle inside your carb body. Clean as necessary.
Flip the carb over so that the cup-shaped diaphragms are facing upward. Remove the four diaphragm screws, being very careful not to strip them. Once the cap is loose, the spring will push it up. Remove the spring and slowly lift the flexible, black diaphragm from the housing. Inspect it for damage and clean as necessary. Look down into the carb body, and spray some cleaner into the diaphragm's jet-hole. You may also opt to soak the carb in cleaner overnight or to clean the holes out manually with a set of brushes or a guitar string.
Repeat with all of the jet holes and spray plenty of carb cleaner. Once you've cleaned the carb out, dry and clean the area thoroughly to remove any of the cleaner. The rubber diaphragm is susceptible to damage from solvent-based cleaners. Reassemble the diaphragm mechanism in the reverse order or removal. Tighten the cover screws hand-tight with a hand driver. About 1/4-turn past snug should suffice.
Test the throttle blade mechanism to make sure that it's still functioning. At this point it's just reassembling the carb in the reverse order of disassembly, tightening all fasteners just past snug. Once you get the bowl mechanism back together, test for movement before you install the float bowl covers. clean everything as necessary as you put the carb back together.
- You might consider just doing one carburetor at a time. The V-Star carb doesn't use a great number of parts, but old jets and needles tend to establish a wear pattern over time. Swapping them around may result in an inconsistent air-fuel ratio.
Items you will need
- Basic hand tools
- Hex-head drivers
- Carburetor cleaner
- "Rebuild and Power Tune Carter and Edelbrock Carburetors"; Larry Shepard; 2010
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