Join Date: Aug 2015
Location: North Vancouver
Year/Make/Model: 2005 Vulcan 800 Classic
Starting at the top of the bike:
1. The petcock should not release gas without the engine running on the "on" or "res" setting, on "pri" it will free flow gas. If yours is letting gas through on "on" or "res" there is an issue. Clean, rebuild, or replace the petcock. Check the tank for sediment, clean if necessary.
2. Clean the carb. Use compressed air on all the jets and passages. After you're 100% sure it's clean, clean it again.
3. Check the float needle for damage or crud, needle seat for damage or crud, and float height.
4. Confirm that the jets are the correct size. Keep in mind that the PO may have drilled them out. The stock jet size will be fine for a stock airbox with aftermarket exhaust. The slide needle isn't adjustable, but check that there aren't any washers, etc. in there. Confirm the idle screw is set to factory setting.
Start there and check back if you're still having an issue. The carb shouldn't be flooding if your petcock and float and float needle are working properly.
Never argue with a fool: onlookers may not be able to tell the difference.