Monday, October 28, 2013
How to Troubleshoot CV Carburetors
Constant velocity carburetors have been standard equipment on Harley, BMW and Kawasaki motorcycles because they work efficiently and dependably with stock and slightly modified engines. They stay in tune well on a vibrating bike, and when they fall out of tune they can be corrected by turning 2 small screws. Common complaints that might be blamed on a CV carburetor are hard starting, poor idling, poor acceleration, poor high-speed performance and poor gas mileage.
Instructions
- 1
Open the petcock. Fully extend the choke knob.
2Start the motorcycle. If the motorcycle is hard to start, ensure that the vacuum operated electrical switch breather hose on top of the air cleaner is connected.
3Turn off the motorcycle. Remove the air cleaner cover with an Allen wrench, Torx wrench or screwdriver depending on your motorcycle. Push the breather tubes on top of the air cleaner down.
4Restart the motorcycle. If the bike is still hard to start, turn off the engine and adjust the throttle and idle cables attached to the throttle cam on the front of the carburetor by turning the cable screws clockwise and counterclockwise.
5Restart the motorcycle and allow the engine to idle. If the motorcycle seems to idle abnormally fast or slow, which is more than 1,000 rpm or less than 900 rpm, adjust the idle screw on the throttle cam with a flat-head screwdriver to tighten or loosen the idle cable. Replace the air cleaner cover.
6Ride the motorcycle in all gears and at all legal speeds. If fuel consumption mileage is less than 40 miles per gallon, the air cleaner filter may be dirty. Park the motorcycle and allow to cool.
7Remove the air cleaner cover with an Allen wrench, Torx wrench or screwdriver depending on your motorcycle. Unplug the breather hoses on top of the air cleaner and remove the air cleaner from the air cleaner backing plate with an Allen wrench, Torx wrench or screwdriver depending on your motorcycle.
8Wash the air cleaner in warm, soapy water. Allow to air dry and oil according to the instructions for your air cleaner. Reinstall the air cleaner and the air cleaner cover with an Allen wrench, Torx wrench or screwdriver depending on your motorcycle.
