How to Fix and Troubleshoot an Enricher Circuit

The enricher is located under the gas tank on this motorcycle.

What is commonly called a “choke”, Harley-Davidson calls an "enricher" on their Keihin CV (constant velocity) carburetors. These carburetors only have high-speed and low-speed circuits, and the term “circuit” describes which of two very tiny nozzles, or jets, inside the carburetor are functioning at any time. Pull on a knob, and the enricher increases the amount of gasoline in the gas-air mix in the low-speed, or idle, circuit. The point of the enricher is to make cold engines easier to start.

Things You'll Need

• Light oil
• Allen wrenches
• Small flathead screwdriver

Instructions

1. Pull the enricher out and push it back in. If the action of the enricher is not smooth, the cable should be lubricated.

2. Pull the enricher knob from the metal clip near the horn. Spray light oil on the enricher cable under the gas tank. Reattach the knob to the clip.

3. Fully extend the enricher and start the motorcycle. Push the enricher knob in halfway after 30 seconds. Push the knob in all the way after another two minutes. If the motorcycle coughs or stalls, the low-speed circuit is probably set too lean. Correct it by the following steps.

4. Close the petcock and run the engine until the carburetor is out of gas and the motorcycle stalls. Turn off the ignition.

5. Remove the air-cleaner cover on the right side of the motorcycle by loosening the screw in the middle of the cover with an Allen wrench. Remove the air filter.

6. Locate the low-speed adjustment screw on the bottom of the carburetor. The screw is at the bottom of a small hole in the center-bottom.

7. Open the petcock and enricher and restart the motorcycle. Push the enricher knob in and run the engine for five minutes. If the engine continues to stall, pull out the enricher knob just far enough to keep the engine from stalling.

8. Turn the low-speed adjustment screw a sixteenth of a turn, counterclockwise, with a small flathead screwdriver. Push the enricher knob all the way in, then fully open and release the throttle. If the motorcycle still stalls, turn the low-speed adjustment screw another sixteenth of a turn counterclockwise.

9. Repeat as necessary but do not give the low-speed adjustment screw more than three sixteenth turns. If the motorcycle continues to stall, the problem is not with the low-speed circuit or the enrichener.

10. Replace the air filter. Reattach the air-filter cover using an Allen wrench.

References

• Mikuni, HSR Choke Cable Installation Tips
• Harley-Davidson; Harley-Davidson Service Manual; 2005
• Paisano Publications; Easy Riders Tech Tips & Tricks, Volume 2; April 1994