I have a 97 vulcan classic 1500D that I bought 2 months ago. At the time, it didn't have a spark and was only firing on one cylinder before that (apparently). I replaced both ignition coils, spark plugs, wires, battery, voltage regulator, cleaned out gas tank and fuel lines, entirely cleaned carburetor. I replaced the main jet to a 132, due to V&H recommendation for using their straight shots. When starting it, the carb is coughing. Once I roll on the throttle a couple times and fire it, usually it starts. Once I warm it up, it will idle beautifully. Once I get it on the road and open it up, it will backfire and stutter when I accelerate. I've gone through all main jet sizes from 132 to a 140, no difference. I've adjusted the pilot screw from 1/4 turn out, to 7 full turns. No change. Everything is clean inside the carb, too. I'm at a loss. Any help is welcomed to get this thing running.

 

Clean again. A good soaking and air blast afterwords works well.

Verify that your diaphrams are not cracked when you inspect. Float height is a must needed check too.
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