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

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old 03-11-2007, 12:22 PM Thread Starter
Members who have donated towards server costs
 
piromedicx's Avatar
 
Join Date: Mar 2007
Location: Rio Rancho, NM
Posts: 203
iTrader: (4)
 
Unhappy flowing fuel and oil

I got a good one. Yesterday my VN750 would not start. We jumped it off. I got a AGM battery coming. We finally got it started and fuel and oil came bubbling out of the front head breather. Then I noticed that fuel had been draining from my K&N pod filter. I pulled the carbs off and opened them up. The float and float valve where free moving. The float valve and seat where also fine. So, I changed the oil, filter, and plugs. Got it started and it started to do it again. My fuel petcock free flows on primary, no flow in the on position. I switched the petcock to on and I stopped.

So here are my questions:
1. What’s making my fuel leak through the carbs?
2. Is that the normal operation for the petcock?


Don Morris
Rio Rancho, NM
VROC #22896
1986 VN 750 "Roxie"
Primer (right now)
Halrey hand controls with badland module
Coastered and de-eared
R/R mod
Iridium plugs
MF Gell Battery
Digital Guard Dawg http://www.digitalguarddawg.com/
Total rewire (after fire)
Vance & Hines Cruzers
Keep The Rubber Side Down.

Last edited by piromedicx; 03-11-2007 at 12:49 PM.
piromedicx is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old 03-11-2007, 03:54 PM
Members who have donated towards server costs
 
Sky Rider's Avatar
 
Join Date: Jun 2006
Location: Corpus Christi, Texas
Posts: 1,647
iTrader: (0)
 
I would assume (I know) that with the petcock free flowing on primary that there is some small peice of crud on the needle valve seat that is allowing fuel to flow even with the bike not running. You may not have seen it when the carb was disassembled. It only takes a miniscule piece of crud to allow fuel to seep by. Or it could be that the valve has a groove worn in the rubber seal that prevents complete closure and therefore a fuel overflow condition.
I'm not sure about your version of the petcock as later models only have off, on, and reserve with fuel flow controlled by vacuum. I would also assume that with your petcock set to on that the vacuum control takes over so fuel won't flow unless the engine is running. I don't know if yours is supposed to free flow in primary or not so someone else with an 86 would have to chime in.

Jim W
93 VN 750 "Ursula"
Moved R/R 08Sep06
R/R rewire 17Feb07
New R/R, Installed 14Jun08
New Stator installed 10 Jun08
Maintenance Free Battery 12Jan08
21480 Miles
VROC #8542
Sky Rider is offline  
post #3 of 14 (permalink) Old 03-11-2007, 04:04 PM
and the Adventure Cycle
 
hyperbuzzin's Avatar
 
Join Date: Jun 2004
Location: Western PA
Posts: 6,138
iTrader: (1)
   
Using "Prime" (it's not "Primary") is the problem. The fuel will flow freely in that position. It isn't vacuum operated like "On" is.
It should only be used when first starting the bike after it's sat for awhile, then switch to on. So Yes, it is normal.
I don't remember which year they changed the petcock to Res-On-Off, but ya may want to consider getting one of those ones.


AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC


"When life throws you curves,
Aim for the apex."

Author Unknown

Last edited by hyperbuzzin; 03-11-2007 at 04:06 PM.
hyperbuzzin is offline  
 
post #4 of 14 (permalink) Old 03-11-2007, 10:29 PM Thread Starter
Members who have donated towards server costs
 
piromedicx's Avatar
 
Join Date: Mar 2007
Location: Rio Rancho, NM
Posts: 203
iTrader: (4)
 
Well that explains how the carbs got the fuel. Now, why did the fuel run into the head? Shouldn't the float valve or the needle valve stopped it in the carb? I am not a mechanic more of a shade tree. I plan on replacing the float and float valve. I don't see a way to replace the float valve seat. I have a old VN750 carb and I drilled the pin on the side of the holding arm and still could not get it out. I had to break the seat holding arms to get it out. I was not planing on replacing the needle they look new. Any input would be greatly received


Don Morris
Rio Rancho, NM
VROC #22896
1986 VN 750 "Roxie"
Primer (right now)
Halrey hand controls with badland module
Coastered and de-eared
R/R mod
Iridium plugs
MF Gell Battery
Digital Guard Dawg http://www.digitalguarddawg.com/
Total rewire (after fire)
Vance & Hines Cruzers
Keep The Rubber Side Down.
piromedicx is offline  
post #5 of 14 (permalink) Old 03-11-2007, 11:53 PM
and the Adventure Cycle
 
hyperbuzzin's Avatar
 
Join Date: Jun 2004
Location: Western PA
Posts: 6,138
iTrader: (1)
   
If there was something ever so small stopping the float valve from fully seating, given some time the fuel would fill the carbs, then flow into the head/cylinder, and if given more time, into the crank case. So it's a good thing that you changed the oil & filter.
Just remember, the petcock should never be left on Prime, and you should be OK.
And, I don't believe that Prime will act the same as reserve, so once your bike starts to sputter out of fuel, you might be totally dry, but ya may want to see if anyone else knows more about that.


AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC


"When life throws you curves,
Aim for the apex."

Author Unknown
hyperbuzzin is offline  
post #6 of 14 (permalink) Old 03-12-2007, 02:59 PM Thread Starter
Members who have donated towards server costs
 
piromedicx's Avatar
 
Join Date: Mar 2007
Location: Rio Rancho, NM
Posts: 203
iTrader: (4)
 
The on position on my peacock does not let enough fuel to flow to get above 30 mph. I have to switch it to prime to run at speed. I looked on bike bandit and the petcock has been discont. I don't really know where to go to find a replacement.


Don Morris
Rio Rancho, NM
VROC #22896
1986 VN 750 "Roxie"
Primer (right now)
Halrey hand controls with badland module
Coastered and de-eared
R/R mod
Iridium plugs
MF Gell Battery
Digital Guard Dawg http://www.digitalguarddawg.com/
Total rewire (after fire)
Vance & Hines Cruzers
Keep The Rubber Side Down.
piromedicx is offline  
post #7 of 14 (permalink) Old 03-12-2007, 03:59 PM
Members who have donated towards server costs
 
fergy's Avatar
 
Join Date: Mar 2006
Location: Kyle, Texas
Posts: 4,054
iTrader: (3)
   
Rebuilding a petcock is not a hard job. You might look for a rebuild kit.

Fergy
Kyle, TX VN750.com member #707 VROC#19556
2002 VN1500 Classic
Spline Lube Procedure, with photos, R/R Relocation and Coil Mod
Rusty Tank Cleaning!
Electrical Fault Finding Flowchart
SEAFOAM JUNKIE!


fergy is offline  
post #8 of 14 (permalink) Old 03-12-2007, 04:29 PM
86 VN750
 
wwmkwood's Avatar
 
Join Date: Feb 2006
Location: Junction City KS
Posts: 227
iTrader: (0)
 
You might also check the vacuum line for cracks or leaks.
wwmkwood is offline  
post #9 of 14 (permalink) Old 03-13-2007, 04:07 AM
and the Adventure Cycle
 
hyperbuzzin's Avatar
 
Join Date: Jun 2004
Location: Western PA
Posts: 6,138
iTrader: (1)
   
Quote:
Originally Posted by piromedicx View Post
The on position on my peacock does not let enough fuel to flow to get above 30 mph. I have to switch it to prime to run at speed. I looked on bike bandit and the petcock has been discont. I don't really know where to go to find a replacement.
Well, if you have to do that, then you'll also have to put it back to on when ya park the bike. Otherwise the fuel will keep flowing, even when not running.

Did you check
part# 51023-1392 - TAP-ASSY,FUEL $57.41 (2006 model)
or
part# 51023-1113 - TAP-ASSY,FUEL (1986 model)
(I don't think Bike Bandit gives the last 4 numbers though)

There are also other model years with different part#'s for the petcock, but #51023-1392 supersedes them all (according to Ron Ayers site anyway).
You should be able to use that one, which is one with reserve, not prime.

Or, like Fergy said, see about rebuilding the one you have.
I'm not sure what's needed for that though.

Did you check the vacuum lines (I didn't really think of that wwmkwood )


AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC


"When life throws you curves,
Aim for the apex."

Author Unknown
hyperbuzzin is offline  
post #10 of 14 (permalink) Old 03-13-2007, 05:41 AM Thread Starter
Members who have donated towards server costs
 
piromedicx's Avatar
 
Join Date: Mar 2007
Location: Rio Rancho, NM
Posts: 203
iTrader: (4)
 
It was the vacume line. replaced it and now it works fine. Thank ya'll (my southern is showing) for all the input.


Don Morris
Rio Rancho, NM
VROC #22896
1986 VN 750 "Roxie"
Primer (right now)
Halrey hand controls with badland module
Coastered and de-eared
R/R mod
Iridium plugs
MF Gell Battery
Digital Guard Dawg http://www.digitalguarddawg.com/
Total rewire (after fire)
Vance & Hines Cruzers
Keep The Rubber Side Down.
piromedicx 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