stumbling at highway speeds - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 4 (permalink) Old 06-16-2013, 02:49 PM Thread Starter
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stumbling at highway speeds

This spring, i took the carbs off my bike, and cleaned them. After the weather finally warmed up, i rode it a few times, and found that when cruising at about 60 or 65, and you go to accelerate, the bike acts funny it kinda shakes/vibrates bad for a while till you let off the throttle. once you let off the throttle enough to stay at your cruising speed, it stops. I know i messed up the fuel/air mixture screw when i took the carbs apart, but i thought i got them back right. Does anyone else have this problem and know how to fix it? also can i get a straight answer on how to fix my fuel/air mixture screws correctly? I think someone said something about turning them till the engine changes in RPM's, but i can't find it again.
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post #2 of 4 (permalink) Old 06-16-2013, 02:57 PM
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I think I read a sticky on this.

Anyway, I used a jewelers screwdriver, turn them in (clockwise) until LIGHTLY seated and back them out to suit your taste. Forum consensus is 2 1/4-2 1/2 turns. Mine are at 2. Factory should be 1 5/8.

Manners (drive-ability) are what you are looking for. Mine will chug along at idle in 3rd gear, i don't need more rich.

Last edited by wmsonta; 06-16-2013 at 03:05 PM.
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post #3 of 4 (permalink) Old 06-16-2013, 03:30 PM
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Did you put the carb vent hose back on, and in the proper place?

If it is loose and air is getting into it at speed it can cause a loss of power.

1986 Kawasaki Vulcan 750
NGK Iridium Plugs #7803/DPR7EIX-9
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Coastered & Shaved
Metzeler ME880 [110/90-19, 170/80-15]
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V&H Cruzers Grill Cover
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1990 Kawasaki Vulcan 750

1998 Honda VFR800 FI

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1989 Pontiac Firebird Formula 350
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post #4 of 4 (permalink) Old 07-31-2013, 11:07 PM Thread Starter
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I took the vent hose, and cut it at 45 degrees, now it runs great.
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