1982 Yamaha XS 400 "vacuum port carburetor fuel petcock" Questions

...for fuel leakage....now manually open the petcock by setting it to the PRI for "prime" position...you will likely see fuel leaking out vacuum port. Kits to rebuild the petcock are readily

...vacuum port on the #3 cylinder (between the carburetor body and the engine) up to the smaller connection on your petcock. When the engine is turning vacuum is applied to this thinner line and allows ...

...port? Is there a fuel shutoff? Hi, Sue always check fuel flow first to isolate the problem area otherwise the usual suspects are: 1. Fuel tank empty. 2. Fuel cap or fuel tank not venting properly. 3. ...