Only 1 Cylinder at Low RPM? - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Electrical
Where does this wire go?
Includes Electrical mods, Lights, Stator,
Rectifier, Diagrams, etc

 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 03-30-2016, 06:12 PM Thread Starter
Junior Member
 
Join Date: Mar 2016
Posts: 21
iTrader: (0)
 
Only 1 Cylinder at Low RPM?

When I first start my bike up, it usually only runs on one cylinder. It won't start firing the second cylinder until about like 2500 or 3k.

After it warms up, it runs a little better at idle to the point where I can hear the other cylinder fire every 5-10 revolutions.

I was wondering if this would be a problem with the spark system? Maybe a bad coil? I replaced the spark plugs a while back and noticed the same problem before and after.

Also, I noticed that cylinder that doesn't seem to fire correctly lean pops really really bad on deceleration.

Any ideas on what to check? Could the carbs just need to be retuned? Or would that affect the whole range of RPMs
snowman4839 is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 03-30-2016, 08:05 PM
1986 VN750
 
thtanner's Avatar
 
Join Date: Nov 2011
Location: Dana Point, CA
Posts: 3,255
iTrader: (8)
 
Garage
Spark is easy to check, take a spare plug, connect it up to the offending coil, hold it against the frame (wearing gloves is always smart) where the bolt part is (to ground it). and fire up the bike. See if you have spark, and what the color looks like.

Could be plugged pilot jets, so best to verify spark before pulling carbs or coils.

1986 Kawasaki Vulcan 750
NGK Iridium Plugs #7803/DPR7EIX-9
Duralast Gold ETX15 AGM Battery
Coastered & Shaved
TOC MCCTs
Metzeler ME880 [110/90-19, 170/80-15]
Balance Dampers Replaced
Tuxedo Mod
Rebuilt Forks w/ Progressive Springs
V&H Cruzers
VN750.com Grill Cover
Meanstreak Seat
Emgo 23-92411 Handlebars
MOSFET FH012AA R/R


1990 Kawasaki Vulcan 750

1998 Honda VFR800 FI

2014 Honda VFR800F

1989 Pontiac Firebird Formula 350
thtanner is offline  
post #3 of 7 (permalink) Old 03-31-2016, 10:03 AM
Old Fart
 
Knifemaker's Avatar
 
Join Date: Jun 2004
Location: Catawissa, MO
Posts: 11,565
iTrader: (4)
     
Garage
Yes if it runs fine at higher rpms I'd say the clogged pilot jet would be the first suspect....

If You Are Not Sure If I Am Joking or Not....I AM !!Photos:
http://www.flickr.com/photos/knifemaker1954/sets/
Knifemaker is offline  
 
post #4 of 7 (permalink) Old 03-31-2016, 11:41 AM
1986 VN750
 
mikesutch's Avatar
 
Join Date: May 2014
Location: Easton PA
Posts: 163
iTrader: (0)
 
Garage
SEAFOAM SEAFOAM SEAFOAM!!!!!

Mosfet R/R and relocated
2 wire Mod for the 1986 harness
VN750.com grill cover
mikesutch is offline  
post #5 of 7 (permalink) Old 03-31-2016, 12:55 PM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,443
iTrader: (5)
   
Agree on everything said so far, try seafoam for a tank of gas and see if that helps before yanking the carbs. Check spark.

If pulling the choke on a little makes it stop missing, I'd add some seafoam.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
Spockster is offline  
post #6 of 7 (permalink) Old 03-31-2016, 06:25 PM
Members who have donated towards server costs
 
Join Date: Mar 2006
Posts: 42
iTrader: (0)
 
Garage
I dunno. I had the same problem with mine. First one of 3 VN750s that did that. After performing Phil's Ear Shave Procedure, all is well. Seems like the cylinder just gets flooded. It was always the rear cylinder on mine. Really weird. Maybe pull the spark plug and get all of the gasoline out of the cylinder?

Sam612
Sam612 is offline  
post #7 of 7 (permalink) Old 03-31-2016, 09:21 PM
FREEBIRDS MC CENTRAL NY
 
OleDirtyDoc's Avatar
 
Join Date: May 2011
Location: Norwich,NY
Posts: 15,868
iTrader: (0)
     
Garage
Send a message via Yahoo to OleDirtyDoc
Mine was flooding on one cylinder.had dirt in the float needle

ONE RATS ASS GIVEN PER POST
Support your local FREEBIRDS MC
1986/5 Vn700/750 Frankenfook cross eyed bitch "Mellisa Fayhe"
I am a BIKER and i'm proud.FREEBIRDS MC CENTRAL NY

lowered with progessive 412 10" shocks
rejetted for K/N Pods part#rc 2340
sportster seat

'I didn't lose my mind.i gave it away

BRING BACK WOLFIE."Peace and Carrots"RIP
"And I'm free...as a bird"John Lennon Free as a Bird
"I only carry when I have my pants on"Joe Robinson RIP aka Old Dog
OleDirtyDoc is offline  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Once registered, your User Name"cannot be changed". We can make exceptions within 7 days, but after that, it is set in stone.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome