Stumped - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
Carbs and Fuel System
From the gas tank to the carbs
All fuel system discussion

 6Likes
  • 1 Post By TonyO
  • 3 Post By bullwinkle
  • 1 Post By bullwinkle
  • 1 Post By JETHRO
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 07-05-2018, 06:20 PM Thread Starter
Addicted to Projects
 
bullwinkle's Avatar
 
Join Date: Apr 2008
Location: Anchorage, AK
Posts: 545
iTrader: (1)
 
Stumped

I've been away for a few years. Had a slip on ice going to work and back surgery/recovery. I'm trying to get my 85 vn700 back up and running after sitting. I've done all the routine stuff and some of the real fun stuff. Found out stater wasn't doing its thing so engine pulled and stater replaced.
But I'm still unable to ride her. In the last month I've pulled the carbs more times than I can count. The bike will idol beautifully but as I turn the throttle it bogs down about 4000 rpm. If I gently nurse the throttle I've gotten it up to around 6000 rpm. I can't ride gently nursing the throttle. I have inline fuel filters that I can see have fuel running through them but it's almost like the bike is running out of fuel.
I'm just stumped.
Any ideas from all you gurus?

Charlie
VN700 project bike 98% completed!!
68 Bushwhacker this winters project (in the works)
86 Honda GL1200i (winter project #2)
82 kz440 daily rider for now!


A few clowns short of a circus now aren't we?
bullwinkle is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 07-06-2018, 11:01 AM
NewB to Vulcans
 
TonyO's Avatar
 
Join Date: May 2016
Location: Orlando, FL
Posts: 171
iTrader: (0)
 
I added an inch of fuel hose to make tank removal easier. Then my bike had the same issues, would run fine at small throttle openings . Turns out the hose was kinked and restricting flow to one cylinder. Took away the extra inch and its just fine. Maybe your addition of the fuel filters is restricting flow?
OleDirtyDoc likes this.

'99 Vulcan "Victoria"
TonyO is online now  
post #3 of 10 (permalink) Old 07-06-2018, 11:30 AM
FREEBIRDS MC CENTRAL NY
 
OleDirtyDoc's Avatar
 
Join Date: May 2011
Location: Norwich,NY
Posts: 15,824
iTrader: (0)
     
Garage
Send a message via Yahoo to OleDirtyDoc
Mine did not like in line filters either

Sent from my Z899VL using Tapatalk

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  
 
post #4 of 10 (permalink) Old 07-06-2018, 12:25 PM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,280
iTrader: (5)
   
Yup, some have had problems using fuel filters, others say their's are working fine.

Make sure all the lines are at least running level to downward, none running uphill. With no filters, upward sloping hoses won't flow well.

Carb vents routed correctly? Problem would show up while moving only.

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 #5 of 10 (permalink) Old 07-06-2018, 03:55 PM
2014 KLR 650!
 
Goofyfoot2001's Avatar
 
Join Date: Jun 2013
Location: Tega Cay, SC
Posts: 3,355
iTrader: (1)
 
Most dramatic fix for my bike was the tw200 petcock mod. Just rode way better when I did that. It's been a while and I could be dreaming but I sold that bike knowing it was working perfect.

2014 Kawasaki KLR 650
Back to the Kawa World
Goofyfoot2001 is offline  
post #6 of 10 (permalink) Old 07-06-2018, 04:38 PM Thread Starter
Addicted to Projects
 
bullwinkle's Avatar
 
Join Date: Apr 2008
Location: Anchorage, AK
Posts: 545
iTrader: (1)
 
I guess I'll get some more new fuel line and give that a try. Thanks all.

Charlie
VN700 project bike 98% completed!!
68 Bushwhacker this winters project (in the works)
86 Honda GL1200i (winter project #2)
82 kz440 daily rider for now!


A few clowns short of a circus now aren't we?
bullwinkle is offline  
post #7 of 10 (permalink) Old 07-07-2018, 01:28 AM Thread Starter
Addicted to Projects
 
bullwinkle's Avatar
 
Join Date: Apr 2008
Location: Anchorage, AK
Posts: 545
iTrader: (1)
 
Removing the inline fuel filters was the ticket. I never thought that would be the case because I simply replaced the old and put new ones on. I was able to get out and put about 30 miles on the bike, the first time in several years. Thanks again.

Charlie
VN700 project bike 98% completed!!
68 Bushwhacker this winters project (in the works)
86 Honda GL1200i (winter project #2)
82 kz440 daily rider for now!


A few clowns short of a circus now aren't we?
bullwinkle is offline  
post #8 of 10 (permalink) Old 07-10-2018, 10:07 AM
Junior Member
 
Join Date: Jan 2009
Posts: 7
iTrader: (0)
 
Those fuel filters build up a clear varnish-like coating over time. Particularly on long idle bikes. Same with petcock. Hot storage locations (outside?) profuce similar conditions.
BillinAustin is offline  
post #9 of 10 (permalink) Old 07-11-2018, 01:08 AM Thread Starter
Addicted to Projects
 
bullwinkle's Avatar
 
Join Date: Apr 2008
Location: Anchorage, AK
Posts: 545
iTrader: (1)
 
Well I didn't have any issues with the other inline fuel filters. They had the goldish colored granular looking filter. The brand new ones I replaced them with were a plastic with a plastic membrane as the substrate. They were positioned identical, very close to straight up and down. The fuel lines were dropping from the petcock through the filters into the carbs. The vulc would still bog down as the rpms went up around 4000. If I nursed it carefully I could work it up to around 6500, but it took some time. It wasn't going to make it for even a quick ride around the block.
After I took the inline filters off, she ran like a dream. It revved up great. I've finally been able to get back into the wind.
I can't explain how or why but without the inline filters it runs great.
roadpouring likes this.

Charlie
VN700 project bike 98% completed!!
68 Bushwhacker this winters project (in the works)
86 Honda GL1200i (winter project #2)
82 kz440 daily rider for now!


A few clowns short of a circus now aren't we?
bullwinkle is offline  
post #10 of 10 (permalink) Old 07-11-2018, 08:05 AM
Senior Member
 
JETHRO's Avatar
 
Join Date: Aug 2012
Location: herefordshire England
Posts: 132
iTrader: (0)
 
Garage
I have noticed that the plastic fuel filters are 6mm dia but you need 8mm dia to run these bikes same as fuel lines.
OleDirtyDoc likes this.

Vn 750 A2 1986 rebuilt engine, crank shaft, half casing,shell bearings,con rods,rear cylinder head,oil pump,water pump ,(had ceased bearing rusted up),tie bar upgrade,clutch basket drilled,front cylinder cam chains,toc springs,stator,shaved, rectifier,agm battery,solenoid ,starter motor (used) re-spray ongoing.

Last edited by JETHRO; 07-11-2018 at 08:07 AM. Reason: wording error
JETHRO 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