Motorcycle Repair: Kawasaki Vulcan Classic 1500 hestitating then gunning on take off., light shades, shades of brown

Question
I have a 98 Kawasaki Vulcan Classic 1500E1 with Thunder Intake and Cobra Pipes. I have noticed that when I drive it for quite a while at high speed, like 30 minutes or so, that if if I come to a stop light for a minute or so when I go to take of it will start of normal then hestitate then gun like it wants to come out from under me. Any suggestions on what to look for or do.

I just change the plugs a month ago but she still runs as smooth as before I replaced them.

Answer
Hi Wade,

From the description given, I suspect the following: tuning the air-fuel miture (jetting) may be necessary, fuel within jets and passageways is starting to varnish, and/or there's an air intake obstruction/restriction (dirty air cleaner).

It's not explaining much, but it's difficult to explain what to do and look for. Review the repair manual for troubleshooting and repair procedures.

Visit www.vroc.com for communicating with other Vulcan owners who may have experienced the same symptoms.

Read the appearance of the spark plugs to learn what's happening inside the cylinder during the combustion process. If the plugs are black and sooty-too rich air-fuel mix. If plugs are white=too lean a/f mix. Light shades of brown are desirable colours for proper working temperatures of spark plugs.

Respectfully,
Mark Shively