Slight miss at around 4.5k - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 13 (permalink) Old 07-30-2009, 08:22 AM Thread Starter
 
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Slight miss at around 4.5k

Still experiencing a miss at times. But sometimes it goes away. Things I have so far are: Run Seafoam through a tank, turn mixture screws out 3 1/2 turns, Cleaned electrical contacts under both side covers. The foam air filters are in pretty rough shape, so I have ordered K&N filters. Where else should I look?
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post #2 of 13 (permalink) Old 07-30-2009, 08:26 AM
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Originally Posted by Slip View Post
Still experiencing a miss at times. But sometimes it goes away. Things I have so far are: Run Seafoam through a tank, turn mixture screws out 3 1/2 turns, Cleaned electrical contacts under both side covers. The foam air filters are in pretty rough shape, so I have ordered K&N filters. Where else should I look?
Since you air filters are shot you are probably running a little lean. Once you install the new filters your problem could be fixed.

Have you installed the NGK DPR7EIX-9 Iridium plugs?


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post #3 of 13 (permalink) Old 07-30-2009, 08:40 AM Thread Starter
 
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Since you air filters are shot you are probably running a little lean. Once you install the new filters your problem could be fixed.

Have you installed the NGK DPR7EIX-9 Iridium plugs?
Thanks for the feedback, yeah, I was wondering about that. The foam was real old, and it just kind of fell off on the bottom of the mesh cage.

No, I haven't installed these plugs. I guess I will try to get some then.
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post #4 of 13 (permalink) Old 07-30-2009, 08:44 AM
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For now you can try opening the screws out to 4.0- 4.5 5 turns is max. Over 3.5 it is a good Idea to put a dab of silicone over the screw so there is no chance of it vibrating out.


85 VN700 "Old Yella"

REBUILT ENGINE
CUSTOM PAINT
VANCE & HINES CRUZERS
EAR SHAVED AND RE-JETTED W/K&N'S
DUNLOP ELITE K591 FRONT & REAR
VOLTMETER
SYNTHETIC BRAKE FLUID
SYNTHETIC OIL & GEAR LUBE
PLEXISTAR 2 WINDSHIELD
SPLINES LUBED
ACCT'S GREASED W/TOC SPRINGS
COASTERD
LEATHER SADDLE BAGS
LEATHER TOOL AND ROLL BAG
PICKUP COILS GAPPED AT .018"
NGK CAP, WIRES, IRIDUMS
BARNETT FRICTION PLATES & SPRINGS
CUSTOM GRIPS, MIRRORS, LEVERS
ORIGINAL STATOR & R/R 14.5v
DEKA MF AGM ETX15L

Best Auto/Moto Insurance | Motorcycle Protection Today | FREE Trade-In Quote
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post #5 of 13 (permalink) Old 07-30-2009, 09:04 AM Thread Starter
 
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For now you can try opening the screws out to 4.0- 4.5 5 turns is max. Over 3.5 it is a good Idea to put a dab of silicone over the screw so there is no chance of it vibrating out.
Thanks for the advice. I am hoping to get the filters in within the next few days.
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post #6 of 13 (permalink) Old 07-30-2009, 10:57 AM
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One of the common problems with a miss at higher rpms is the vent hose in the right air filter bottoming out. Since your filters are shot this may well be the actual cause of the miss at higher rpms too.
Check the vent hose and make sure it is seated properly and the tip is cut at a 45 degree angle.
With new filters and the vent hose getting proper air flow the miss should disappear. You will most likely want to adjust the air mix screws back down to about 2 3/4 with the new filters too. 3 and a half is usually a bit much with stock.

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post #7 of 13 (permalink) Old 07-30-2009, 02:36 PM Thread Starter
 
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Quote:
Originally Posted by Dianna View Post
One of the common problems with a miss at higher rpms is the vent hose in the right air filter bottoming out. Since your filters are shot this may well be the actual cause of the miss at higher rpms too.
Check the vent hose and make sure it is seated properly and the tip is cut at a 45 degree angle.
With new filters and the vent hose getting proper air flow the miss should disappear. You will most likely want to adjust the air mix screws back down to about 2 3/4 with the new filters too. 3 and a half is usually a bit much with stock.
I will check that vent hose. I take it that it pinches off at the bend?? Thanks!
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post #8 of 13 (permalink) Old 07-30-2009, 07:47 PM
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Some times it will botom out and cause fuel flow problems, cutting the hose at an angle eliminates this problem.


85 VN700 "Old Yella"

REBUILT ENGINE
CUSTOM PAINT
VANCE & HINES CRUZERS
EAR SHAVED AND RE-JETTED W/K&N'S
DUNLOP ELITE K591 FRONT & REAR
VOLTMETER
SYNTHETIC BRAKE FLUID
SYNTHETIC OIL & GEAR LUBE
PLEXISTAR 2 WINDSHIELD
SPLINES LUBED
ACCT'S GREASED W/TOC SPRINGS
COASTERD
LEATHER SADDLE BAGS
LEATHER TOOL AND ROLL BAG
PICKUP COILS GAPPED AT .018"
NGK CAP, WIRES, IRIDUMS
BARNETT FRICTION PLATES & SPRINGS
CUSTOM GRIPS, MIRRORS, LEVERS
ORIGINAL STATOR & R/R 14.5v
DEKA MF AGM ETX15L

Best Auto/Moto Insurance | Motorcycle Protection Today | FREE Trade-In Quote
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post #9 of 13 (permalink) Old 07-30-2009, 11:36 PM Thread Starter
 
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I dont see this vent hose, anyone have a pic of it.

I just filled the tank up, and the problem went away!
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post #10 of 13 (permalink) Old 07-31-2009, 10:55 PM Thread Starter
 
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I installed the K&N's and turned the screws back in to 2 3/4 out. I think this fixed the 4-5k hesitation problem. It started raining so I didn't have a lot of time to test it. We shall see to tomorrow.
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