I have a 2006 Kawasaki Vulcan 500 with about 2000 miles on it. It was running fine when, right before Thanksgiving, I decided to adjust the valves. The valves were too loose at first, but I adjusted them again and I think they’re fine. But there’s another problem. The bike starts fine and runs ok on full choke, but when I take half the choke, it doesn’t sound so great, although it does still idle. However, as soon as I try to open the throttle a bit, it dies on me. My theory is that when I was sloshing the fuel around, some gunk from the bottom of the tank got into the carbs. I pulled them off and cleaned them, to no avail (they looked pretty clean even before I started). Before I pull them off to try to clean them again, do you agree that the carbs are very likely the problem? If they’re not (i.e., if there were an ignition problem or a loose vacuum hose, I don’t know why it would run fine with with the choke on.
Yes. I agree – the carbs are more than likely your problem. Check, recheck, and triple check that your pilot jets are clear, that your main jet is flowing well, and your needle is clean and free of debris. Squirt some cleaner or wd-40 or compressed air through every passage of the carbs, it should come out somewhere – if it doesn’t the passage is dirty.