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

 9Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 48 (permalink) Old 04-20-2018, 07:12 AM Thread Starter
Senior Member
 
dunthyon's Avatar
 
Join Date: Dec 2017
Location: Virginia Beach, VA
Posts: 111
iTrader: (0)
 
Garage
Sluggish running and guzzling fuel.

Hey all. So the fork situation I had earlier is finished with, No more leaks. Now the next and probably final issue; I don't think I'm letting it idle on choke long enough but the bike seems to fire only on one cylinder or is starved for fuel after a half mile riding, it feels like POOGS but never stalls. The other thing is after 23 miles my gauge reads at half full tank. What gives?

This is my first bike over 250 by the way so I may just be doing bad habits that the Rebel taught me.

I have a love/hate relationship with this bike I swear to God.
dunthyon is offline  
Sponsored Links
Advertisement
 
post #2 of 48 (permalink) Old 04-20-2018, 08:34 AM
Senior Member
 
ubertalldude's Avatar
 
Join Date: Jun 2016
Location: NE Florida
Posts: 662
iTrader: (0)
 
Has the bike sat for a while? Sounds like a clogged float needle if it's only happening on one cylinder. Tap on the carbs and maybe toss some seafoam in the gas? Realistically these bikes should get around 35-40+ mpg if they're not re-jetted, even with a twisty wrist. Stuck closed float would cause one cylinder to starve for fuel, but it'd have to be flooding like crazy and running stupid rich to eat half a tank in 23 miles. Then again, the gas gauge on these isn't the most indicative of actual fuel level. I typically count on 120 miles on a full full tank (all 2.7 gallons, filled to the bottom of the filler neck), but the gauge reads empty probably around 90-100 miles (with about 1/2 gallon left, I reckon).
OleDirtyDoc likes this.

Earshave+Rejet (38/135) – NGK Iridiums – MCCT Conversion – Slipstreamer S03 Windshield – Custom Extended Backrest – Custom Highway Bars – MOSFET R/R – LED Underglow – Volt+USB In-Dash – Two-Wire & Blue-Wire Mod – Satin Black Engine Paint – Dampers Parts - Jets: Main=99101-393(#132 stock)/Pilot=n424-22 Pilot(#38 stock)
ubertalldude is offline  
post #3 of 48 (permalink) Old 04-20-2018, 08:53 AM
GDI
Senior Member
 
Join Date: Aug 2017
Location: Madison, WI
Posts: 170
iTrader: (0)
 
No answers here. . . .

I would "punt"! I've used Berryman's B12 fuel additive for cleaning carbs with some success in the past. I'd try that first. It's a fuel additive that you put in the gas tank. Bought mine at Walmart.

https://www.walmart.com/ip/Fuel-Syst...eaner/16817404

If it doesn't work, you're only out $6. Never had much luck with Seafoam, but some swear by it. . . .

Chances are if it's running on one cylinder, expecting any additive to work may be a pretty big ask. To my mind, a complete blockage is going to keep the additive from getting where it needs to be to do its job.

UberTall's diagnosis sounds like a problem I had in the past. I took a tank in to get painted, and when it came back I added a fuel line filter. Painter must have primed it with no covering over the fill hole because the filter and float valve were getting filled with crud that looked like primer "dust" to me. Took getting stranded with a bike that wouldn't run several times for that to work itself out! Not fun.

That said--could be an electrical issue with bad coil, or spark plug wires, or, ???? Then the fuel additives are going to do nothing for you. Maybe someone else will come by with another idea.

GDI
GDI is offline  
 
post #4 of 48 (permalink) Old 04-20-2018, 09:51 AM Thread Starter
Senior Member
 
dunthyon's Avatar
 
Join Date: Dec 2017
Location: Virginia Beach, VA
Posts: 111
iTrader: (0)
 
Garage
I probably should have mentioned she just got out of the shop a couple weeks ago! They cleaned and repaired the carbs to be brand new and the tank got a new coat inside. So it shouldn't be an actual fuel delivery issue, if it is I think that shop screwed me.

I have a love/hate relationship with this bike I swear to God.
dunthyon is offline  
post #5 of 48 (permalink) Old 04-20-2018, 10:12 AM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,483
iTrader: (5)
   
Did this happen just one time, or repeats every time you take the bike out?

For now, I would say look at the plugs and let us know what color you find on them. Can also check the spark, note color and strength. Is the spark blue with a quick *snap*, or orange/yellow and just sort of lights up?

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

Last edited by Spockster; 04-20-2018 at 10:26 AM.
Spockster is offline  
post #6 of 48 (permalink) Old 04-20-2018, 10:13 AM
Senior Member
 
Join Date: Nov 2015
Location: Pittsburgh, PA
Posts: 1,008
iTrader: (0)
 
Garage
After running on one cylinder, are the spark plugs dry or wet?
OleDirtyDoc likes this.

1992 US-nonCA * tuxedo mod * r/r relocated

Vulcan slang for newcomers
Service Manual Download
Wiring Diagram + annotations * still undergoing revisions, but still more useful than the generic one. Let me know if you find mistakes or think something additional should be added
Thorn is offline  
post #7 of 48 (permalink) Old 04-20-2018, 12:54 PM Thread Starter
Senior Member
 
dunthyon's Avatar
 
Join Date: Dec 2017
Location: Virginia Beach, VA
Posts: 111
iTrader: (0)
 
Garage
Not sure yet, will give it a look once I get home! I'll let it choke until it revs up to 3k on its own then see if it does it again.

I have a love/hate relationship with this bike I swear to God.
dunthyon is offline  
post #8 of 48 (permalink) Old 04-21-2018, 05:22 PM Thread Starter
Senior Member
 
dunthyon's Avatar
 
Join Date: Dec 2017
Location: Virginia Beach, VA
Posts: 111
iTrader: (0)
 
Garage
I pinpointed the issue down to a blocked gas tank cap vent and non-existent carb vent lines. Would not having carb vent lines cause this kind of power loss and crap? I would imagine so.

I have a love/hate relationship with this bike I swear to God.
dunthyon is offline  
post #9 of 48 (permalink) Old 04-21-2018, 10:40 PM
Senior Member
 
Spockster's Avatar
 
Join Date: Nov 2012
Location: WV
Posts: 6,483
iTrader: (5)
   
Quote:
Originally Posted by dunthyon View Post
I pinpointed the issue down to a blocked gas tank cap vent and non-existent carb vent lines. Would not having carb vent lines cause this kind of power loss and crap? I would imagine so.
Wind hitting the vents will cause bogging, because the positive air pressure prevents fuel flow into the bowl on a gravity feed .

Vent lines need to run into dead air space. There's a spot to put the hose onto either ear (air filter box), or if earshaved, the blank 'nipple' on the fuel gauge sender cover (bottom of gas tank) is the best place. Even vent lines with a filter on the end can have problems with wind.

Hose plugged into the ear needs cut at a 45° angle so it doesn't block off against the back wall of the ear.
WilliamTech3 likes this.

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 #10 of 48 (permalink) Old 04-22-2018, 10:17 PM Thread Starter
Senior Member
 
dunthyon's Avatar
 
Join Date: Dec 2017
Location: Virginia Beach, VA
Posts: 111
iTrader: (0)
 
Garage
I appreciate the response Spockster! I'm gonna be in for hell getting these hoses on (because I refuse to remove those carbs. Got one hose on, just got the other now!) but I'm glad it'll solve my bogging issue. I already fixed the POOGS issue!

And since I'm scatterbrained and can't collect my thoughts properly, I accidentally created a new issue! I used 3M Trim/Emblem Adhesive on the tank for my emblems and it ate the very custom paint job in the emblems' spots. I'm gonna be getting a decal for it to try and cover it up and make it work. Before I start, anyone have any ideas on that one?

I have a love/hate relationship with this bike I swear to God.
dunthyon 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