The float in the Mikuni carburetor on your Yamaha Wolverine helps to maintain a good balance of air and fuel in the engine. By allowing a certain amount of fuel and air to pass into and out of the carburetor, the float keeps the engine running its best. If your float is out of adjustment, the height of the float being too low or too high, the fuel/air mixture will be either too rich (too much fuel) or too lean (too much air). Learn to adjust the float height on your Mikuni carburetor and keep your Wolverine running great.
Remove the carburetor from your Wolverine. Turn the fuel petcock to the "OFF" position, and lift the seat. Locate the carburetor between the air filter box and the cylinder head of the engine. Loosen the clamp around the outlet of the carburetor (the side closest to the cylinder head), then pull the carburetor out of the Wolverine.
Remove the four float bowl screws on the top of the carburetor, and pull off the carburetor float bowl cover. Inside, you should see a white plastic "float." The height of this piece of plastic from the fuel inlet below is what you will be adjusting.
Use a set of vernier calipers to measure the height of the float above the metal surface of the float bowl in millimeters. Be careful not to compress the float into the bowl when measuring or you will not get an accurate measurement.
If the engine has been running too rich, as evidenced by higher-than-usual idle speed, or crawling acceleration from a stop, reset your vernier calipers to 1 mm smaller than the measurement you took previously. If it has been running too lean, as evidenced by low idle or low power at high revs, set the vernier calipers to 1 mm larger than the previous measurement.
Locate the float spring, a small metal tab between the two large plastic parts of the float. Bend the tab upward slightly using a slotted screwdriver or similar tool to raise the float height 1 mm, or bend the tab downward slightly to lower the float height 1 mm. Check the accuracy of your work using your vernier calipers.
Reattach the carburetor to the Wolverine, and take it out for a test ride. You should notice an immediate difference in the idle speed of the engine and an increase in power throughout the rev range if your adjustments were correct.
