1/8 to 1/4 hesitation - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 4 (permalink) Old 06-14-2017, 08:59 PM Thread Starter
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1/8 to 1/4 hesitation

Im new to the Vulcan and just picked up an 98. Im having an issue with throttle response from about 1/8th to 1/4. It seems like the bike wants to die and shutters when trying to cruze in that range.
The bike seems to surge when I try to cruze in that range which usually is between 2800-4200RPM. If im at say 3200 RPM and have load trying to say get up a hill the surging goes away.
The only modifications I know of are very aggressive straight pipes. Im not sure what if anything has been messed with inside the carb. The bike was sitting for about a year before I picked it up so I figured maybe crap in the carb but they seem fine.

its really annoying rolling through corners, I can back off and glide but when I try to smoothly roll out of it, from 0-1/8 it pulls and then from 1/8 to 1/4 it almost dies and then it pulls again.
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post #2 of 4 (permalink) Old 06-15-2017, 09:51 AM
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most likely hesitation from the carbs being gummed up if it sat for a year. Seafoam or some other carb/fuel injector cleaner might help a bit, but they'll probably need to be pulled and deep cleaned.

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post #3 of 4 (permalink) Old 06-15-2017, 12:36 PM
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Sounds like a clogged pilot jet in the carb. The pilot jet, responsible for idle and low end acceleration, is usually the smallest passage in the carb and easily clogged. Seafoam (or your favorite carb libation) may work if the clog is varnish (old gas), but pulling the carbs may be necessary if the clog is physical (e.g., grain of sand).

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post #4 of 4 (permalink) Old 06-15-2017, 02:09 PM
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Dirty pilot circuit was my first thought as well. The higher rpm surge is probably the main circuit starting to clog up.

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