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Inzane 17

Fuel leak

Started by M.Kyzer, Thu 20, Sep 2018, 07:05:23

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M.Kyzer

Went to ride the valk to work this morning but I could smell gas really strong. Had to use my phone flashlight to see but gas was pouring out behind the middle carb right side up under where I couldn't  see. Would start leaking  as soon as u turned the petcock on even with the bike not running. Any ideas where to start looking when I get home to find the leak.

Chrisj CMA

I would start with the middle carb on the right side.   :crazy2: :2funny:

Sorry couldn't help it.

Sounds like fuel rails. If I'd doesn't stop on it's own you're going to have to pull the carbs.

longrider

How many days had the bike been sitting before you rode it. It takes a long time for the fuel rail o-rings to dry out.  Also if the fuel leaks when you turn the petcock on with the bike Not running,  the vacuum operation is not working correctly and needs a rebuild

M.Kyzer

Bike was parked only 1 week. Petcock was replaced about 2 months ago.

Bagger John - #3785

As Chris pointed out: Fuel rails. Specifically, the O rings used in all the joints.

Go to an online microfiche and order the required quantity of every O ring used in the carb assemblies then replace them while the banks are apart. If one failed, the others are probably right behind.

Roidfingers


Daniel Meyer

Quote from: M.Kyzer on Thu 20, Sep 2018, 08:58:55
Bike was parked only 1 week. Petcock was replaced about 2 months ago.

Yep, sounds like fuel rails...

Also:

Was the petcock replaced with OEM? 'cause that's not working right if the fuel leaks right when you turn it on...

CUAgain,
Daniel Meyer

M.Kyzer


Daniel Meyer

Quote from: M.Kyzer on Thu 20, Sep 2018, 10:44:15
Yep OEM ....

Welp...ya need to test its functionality when you're got stuff apart to fix the actual leak.

-dm
CUAgain,
Daniel Meyer

longrider

#9
A month ago I purchased a new to me valk IS    Last week I removed the tank to install a new air filter.  Every time I remove the tank on on either of my Valkyries I check the operation of the petcock    The tank is set on a table with the petcock hanging over the edge just far enough so a hose Can be attached to the outlet. A catch container is used for the fuel.  A small length of hose is attached to the vacuum side.  Open the petcock. Nothing should flow.  Apply vacuum.  Fuel should flow.  Remove vacuum and fuel should stop.  Repeat a couple of times.  I always have a spare cover set In my parts bin

Dusty

Quote from: longrider on Fri 21, Sep 2018, 17:25:55
A month ago I purchased a new to me valk IS    Last week I removed the tank to install a new air filter.  Every time I remove the tank on on either of my Valkyries I check the operation of the petcock    The tank is set on a table with the petcock hanging over the edge just far enough so a hose Can be attached to the outlet. A catch container is used for the fuel.  A small length of hose is attached to the vacuum side.  Open the petcock. Nothing should flow.  Apply vacuum.  Fuel should flow.  Remove vacuum and fuel should stop.  Repeat a couple of times.  I always have a spare cover set In my parts bin

To go along with that routine I would spray some wd- 40 or parts cleaner aerosol into the vacuum port to flush out any specs of dirt or debris that could  plug the little hole in the attached pictures. When that tiny hole gets plugged up the petcock does not close when the engine is shut off.

Dusty





Daniel Meyer

Quote from: Dusty on Sun 23, Sep 2018, 01:25:52
Quote from: longrider on Fri 21, Sep 2018, 17:25:55
A month ago I purchased a new to me valk IS    Last week I removed the tank to install a new air filter.  Every time I remove the tank on on either of my Valkyries I check the operation of the petcock    The tank is set on a table with the petcock hanging over the edge just far enough so a hose Can be attached to the outlet. A catch container is used for the fuel.  A small length of hose is attached to the vacuum side.  Open the petcock. Nothing should flow.  Apply vacuum.  Fuel should flow.  Remove vacuum and fuel should stop.  Repeat a couple of times.  I always have a spare cover set In my parts bin

To go along with that routine I would spray some wd- 40 or parts cleaner aerosol into the vacuum port to flush out any specs of dirt or debris that could  plug the little hole in the attached pictures. When that tiny hole gets plugged up the petcock does not close when the engine is shut off.

Dusty






This is why in the "cover set" oem rebuild kit...they include that entire cover...that little hole/etc is a dampener...to reduce the intake backpulse from our rather aggressive cam timing...without it (and many aftermarket or "oem style" petcocks don't have it), the diaphragm will shred in  a matter of days.
CUAgain,
Daniel Meyer

dmerc

Should be easy to see if it's the fuel rail, with a small dental mirror and flashlight.  I did mine this spring, but did not remove the manifolds on the left side, only the ones for carbs # 3 and 5 (my leaker) Remove the support bolts tieing the banks together, then slid #5 carb over far enough to replace the o-rings..... $1.40 at NAPA, and a few hours of work. Saved a little time not pulling the entire bank of carbs. My #5 carb separated pretty easy (luckily) (watch those springs when separating)