Kawasaki Vulcan Hesitation

SO I recently got a 98 Kawasaki Vulcan 800. The problem is it has a low throttle low speed hesitation. It runs good at highway speeds but when getting going it sometimes hesitates/stumbles when I give it just a little throttle. It is worse when cold but still sometimes does it when warm too. It is random some days it does some days it doesn't.

So far I have done: Richen the mixture with the pilot screw, Total maintenance baseline (plugs, valves, fluids) changed the leaky petcock. Tried cleaning the jets out and also tried seafoam.

Any Ideas?

Single diaphragm type carb? Most bikes are jetted way lean on low end from the factory try 1 size up on the pilot jet. There may also be an air correction jet for the top diaphragm make sure that is clean. if it has any type of aftermarket air filter make sure the rubber color doesn't restrict air flow to the holes and slots around the outer edge.

I think I figured it out. I found a vacuum leak at the carb mounting boot. Now I just have to figure out the voodoo trick to getting it at the right tightness.

If the boot is leaking because it's fractured (common with the passage of years), a smearing with a gasoline proof sealant will do the job.

Don't mess with trying to seal a leaky boot by a new one its $30 well spent not blowing up the motor or sitting on the side of the road when it decides to rip completely. You may also want to replace the captive O-rings in the head to manifold junction may be $10 for the two.

I ordered a new boot and the two orings. I also ordered one size up pilot jet and a cv performance ez-adjust mixture screw. Hopefully this fixes my problem.

Good call. What did it run you?

The boot was right at $30 and the orings were $10 apparently Kawasaki is doing something with their warehouses and it will take a week to get here. The jet and screw were right at $30 too. Also heard that shimming the needle might help.