Kawasaki VN750 Forum banner

1 - 20 of 35 Posts

·
Registered
Joined
·
268 Posts
Discussion Starter #1
Hello again!

I've spent some time searching and while I've found many who have experienced this problem, I failed to discover a solution aside from "open the cap and let it sit for a few"!

I was on a nice ride with some buddies Wednesday, just about 100 miles. When I got to half a tank, we had just met another buddy and started riding when Vanessa started sputtering and finally died on me. I tried to switch to the reserve tank, tried to pop the clutch a few times, and finally had to stop to pull over and open the tank. After a few minutes things were fine. We continued along and as we headed home it happened again at about 1/4 tank! Same thing, let her breathe and I made it home!

This is SOOO frustrating, as I'm sure many of you know! But I'm planning to be riding to D.C. with 40-60 other bikes at the end of May and I NEED to get this resolved before then. Can anyone help me with a permanent solution to this madness?

Thanks again! All input is appreciated.
 

·
Premium Member
Joined
·
4,054 Posts
That has to be frustrating! If you think about it, it has to be something that is clogging the venting system through the filler cap. I had my bike for 3+ years and put nearly 20,000 miles on it and never had it happen to me. I remember some who found small blockages in the vent, but I don't know how to tell you where to look for it. Seems like using a small piece of wire poking through the vent and/or blowing air through a rubber tube, some were able to remove a small bug that had crawled in there or some dirt or something and the problem went away. I'm just saying, it has to be something that can be fixed in my opinion, considering I had the same bike for 3 years and 20K miles without ever experiencing that problem... I hope others will offer up suggestions for where to look and clean the vent!

Of course, the vent from the carb getting bottomed out in the right ear also causes a similar problem, but I'm sure you've checked that and probably cut the 45 degree into the end to keep it from bottoming out...
 

·
Old Truck Junkie
Joined
·
4,133 Posts
Take the cap apart and clean it.
Another problem that I have had is that the engine will stall after sitting in HOT weather. I have decided that it is high pressure in the fuel tank causing it to flood after the needle valve opens. The pressure causes a surge of fuel to enter the carbs and causing them to flood. From now on I am going to release the pressure before start up.
 

·
Registered
Joined
·
738 Posts
My Phantom has been uncloaked!

I just went through this on my ’06 (non-CA model), exact same situation too (stall at ½ tank gas). Try this (again '06 non-CA model, other models and CA emissions may differ):

Step 1: Clean the gas cap vent tube:

  1. Place a piece of paper in front of the REAR tire
  2. Open the gas cap
  3. Spray carb cleaner into the vent tube located on the tank, near the base of the gas cap hinge. Use the straw attachment for the spray can.
  4. Observe the drips onto the piece of paper. Continue spraying until it runs clear.
Step 2: Clean the gas cap vent mechanism

  1. Open the gas cap and remove the key.
  2. Cover the tank inlet tube with tape or a piece of paper to prevent dropping things in the tank. I used a large PostIt note, which worked well.
  3. Remove the two brass screws that hold the latch mechanism on the bottom of the gas cap.
  4. Remove the latch mechanism. Note: there is a loose component in the base that covers the latch spring. Be careful not to drop it into the tank during removal. Inspect the latch, clean as necessary (chances are this is NOT where the problem is), then set aside.
  5. Careful not to loose the 5 small springs mounted on posts under the latch mechanism. You can leave them where they are or remove them for safe keeping.
  6. Before proceeding remove the small collar from the male latch connector (look for the round key cylinder). The collar acts like a bearing when opening and closing the latch using the key. It is loose and easily lost. Slip it off and put it aside for safe keeping.
  7. Remove the two short screws at the base of the gas cap vent, but DO NOT yank the vent off yet.
  8. The vent gasket is glued to the cap (at least it was on mine) and the vent assembly might be stuck to the gasket. GENTLY, wiggle the vent back and forth to loosen it and prevent damage to the gasket.
  9. With the vent assembly removed, inspect the gasket for tears or bulges. Spray with carb cleaner (just a little) and wipe with a clean cloth. Inspect the cloth for signs of debris.
  10. Now for the root of the problem; Remove the small round plastic check valve/liquid separator located on the underside of the vent assembly. GENTLY ply it out, careful not to damage the silicone valve covering the base of the check valve. Remove the gasket as well and place it aside. Inspect and clean the check valve, ESPECIALLY the tiny 90 degree elbow which leads to the vent hole. NOTE: there is another silicone valve cover permanently mounted in the gas cap vent itself (part of the pressure release part of the valve). DO NOT attempt to remove it or you will damage it. Just make sure it is clean and functioning.
  11. Now check the vent hole. Hold the vent assembly up to the light and look up from where the plastic check valve was mounted. See any light where that tiny 90 degree elbow fits? Follow the vent channels on the opposite side of the vent assembly. Any blockage? Unplug the holes and clean the channels.
  12. Reassemble.
Step 3: Repeat Step 1 frequently (at least once a year) to prevent this from happening again.

UPDATE 5/5/2010: My Phantom has been uncloaked! I took a closer look at where/how the rubber vent tube exits in front of the rear tire. I found that the tube had been (and still is) rubbing against the rear tire. The 'black fluffy carbon' blocking my vent was probably rubber shavings caused by the vent tube rubbing against the tire. I've temporarily rerouted the vent tube to exit along side the coolant overflow tube to eliminate the vent tube/tire rubbing. I still plan to flush the vent once a year to reduce the possibility of dirt and dust reaching and blocking the actual gas cap vent.
 

·
Registered
Joined
·
722 Posts
Cleaning out the vent tube that runs from under the cap to the tube under the seat with mechanics wire did the job for me!!!!
 

·
Giggity!
Joined
·
4,307 Posts
Dumb question here. If I'm understanding it right. The hose attached at the back of the tank is associated to the small hole by/under the gas cap. Which then is vented via the cap? I've never cleaned that passage but I have had my cap apart & cleaned. I was leary of shoving or spraying anything in there. I didn't really know where it went. I had an idea, just never asked. That would be an easy fix.
 

·
Registered
Joined
·
738 Posts
The hose attached at the back of the tank is associated to the small hole by/under the gas cap.
Yes.

The vent line/hose operates in both directions; sucking air in to relieve vacuum and venting air out to relieve pressure ('06 model, older models and CA emissions might differ). If there is dirt in the vent line, then it could/will be sucked into the gas cap vent hole eventually.

In my case the vent line was loaded with fluffy black carbon (probably oxidized fuel). I suggest placing a piece of paper in front of the rear tire (where the vent exits) before flushing the vent line. Use the flush drippings on the paper to visually inspect the conditions of the line (i.e., drips are black or dirty, so clean the gas cap vent as well)

The vent line on my well maintained '06 with only 9K miles was pretty dirty. That's not a lot of time or mile and tells me that I need to flushing the vent line often, at least yearly. I'll bet that simply flushing the vent line often will reduce, if not completely eliminate, the phantom out of gas syndrome.
 

·
Calif Rider
Joined
·
725 Posts
On Calif smog control bikes, the watching for fluid to drip from tube at rear tire will not work. The tube from the rear of the tank goes to a breather box , no fluid will drip from any line. Like Bman said you can try to clean it out to the tube that is at the rear of the tank. The tube from the tank to the breather box, you can remove it and see if it is clogged by flushing it out.
 

·
Registered
Joined
·
268 Posts
Discussion Starter #9
Ok, well I've disassembled the cap and cleaned everything out there. I also sprayed brake cleaner into the vent and hose to ensure it was clean. No issues with passage and only a slight bit of yellow in color for about 15 seconds then clean as vodka.

I'm about to put it all back together and go for a spin, but it seems so weird that there was NO apparent blockage! :confused:

As I sit here writing this, I'm also going to add blowing some air through the vent line to see if anything comes out.
 

·
Premium Member
Joined
·
1,126 Posts
So, i need to spray directly into the vent hole in the cap? then it will drain out the front tire area?
 

·
Registered
Joined
·
738 Posts
So, i need to spray directly into the vent hole in the cap? then it will drain out the front tire area?
No.

Open the gas cap and locate the vent tube on the tank itself, located at the base of the gas cap hinge. It is a small hole on the tank with a raised rubber washer/nipple. That hole passes through the tank and exits at the base of the tank, just under the front of the seat. There it connects to a rubber hose that exits in front of the REAR tire. Spray into that portion of the vent and observe it draining in front of the rear tire.
 

·
Registered
Joined
·
738 Posts
Ok, well I've disassembled the cap and cleaned everything out there. I also sprayed brake cleaner into the vent and hose to ensure it was clean. No issues with passage and only a slight bit of yellow in color for about 15 seconds then clean as vodka.

I'm about to put it all back together and go for a spin, but it seems so weird that there was NO apparent blockage! :confused:

As I sit here writing this, I'm also going to add blowing some air through the vent line to see if anything comes out.
Stumped. Your symptom are exactly what I was experiencing. However, upon disassembling my gas cap I found that the tiny vent hole was physically blocked and the vent tube full of carbon. After cleaning my bike is now back to normal (I even hear the slight whistling from the gas cap that indicates that the vent is functioning).

Maybe that 'yellow color' you described was a big old plug of pollen in the vent tube and the brake cleaner dissolved it (guessing here)? How did your test ride turn out?
 

·
Registered
Joined
·
268 Posts
Discussion Starter #13
Not too sure what it could have been.

Before dismantling the cap yesterday, I had heard the whistling on a regular basis. It drove me crazy which is what made me think this whole thing was a result of the Phantom Out of Gas issue, but I have no clue. I filled her up with some gas last night and rode without incident and am just about to head out again for a bit. I'm hoping this doesn't happen again. It's going to be frustrating and embarrassing if I have to break rank or slow the whole pack down when I head to D.C. with 30-40 other bikes.
 

·
Love My Baby
Joined
·
1,165 Posts
The POOGS happened to me a couple times. But now I routinely open my gas cap for a second before I start up. Hoping that relieves the vacuum that could be causing this whole mess. Easy fix. No symptoms since I started doing this, but then again it only happened sporadically.
 

·
Linkmeister Supreme
Joined
·
7,960 Posts
Stick a spare key in the tank cap lock when you ride, if you think the POOGS is happening you can quickly open the cap to relieve any vacuum, and let the engine keep running. Worth a try anyway.
 

·
Premium Member
Joined
·
641 Posts
I read either on here or on the yahoo group where some one removed the two white and red diaphragms in the gas cap and never had a problem since. I did this myself and have not had a problem with PGS since either.
 

·
Registered
Joined
·
738 Posts
My phantom has been uncloaked! See update to my post above dated 4-30-2010 (the one with the gas cap vent cleaning instructions).
 

·
Registered
Joined
·
47 Posts
I read either on here or on the yahoo group where some one removed the two white and red diaphragms in the gas cap and never had a problem since. I did this myself and have not had a problem with PGS since either.
Okay... I've been fighting this problem for the 4 years that I've had this '95. Very dangerous in traffic, and embarrasing when my co-workers all passed me sitting by the side of the road waiting for it to vent. I did a Poker Run last Sunday, and it did it 3 times. I just went out and took the cap apart, and found that the top diaphram (they are both red) was torn. So, I figured, WTF, I just took both of them out. I'll find out tomorrow if it works. I used a 1/4" piece of tubing to blow & suck through all of the little holes and the rubber one that leads to the bottom of the bike, and they were all clear. I had been blaming this problem on the vacume actuated fuel valve on the bottom of the tank, and me and some epoxy & diaphram removal fixed that to be always on, so that I HAVE to use the OFF position of the valve when I shut it down in case it wants to leak all over the parking lot in the sun, just like the bikes I grew up with (I'm 62 YO, and I've had a few... ). I'll report back in a couple of weeks after giving it a thorough testing.

--Buck
 

·
Registered
Joined
·
78 Posts
Summer before last I had the same POOGS. After opening the gas cap it would run fine for a while, heck I was even riding with a spare key in the cap. It was really pissing me off. One day I decided to find out what was really happening. Once I took the seat off I noticed a shine mark on my vent hose. Seems a few week prior I had the seat off to do some electrical work. Evidently when I rerouted the new wire I accidentally rerouted the vent tube, so when I sat on the seat it was pinching off the vent tube.
Once I put the vent tube back where it belonged the problem was solved.:BLAM:
 

·
Registered
Joined
·
738 Posts
... One day I decided to find out what was really happening. Once I took the seat off I noticed a shine mark on my vent hose. Seems a few week prior I had the seat off to do some electrical work. Evidently when I rerouted the new wire I accidentally rerouted the vent tube, so when I sat on the seat it was pinching off the vent tube.
Once I put the vent tube back where it belonged the problem was solved.:BLAM:
I think that the vent tube is the root of the POOGS problem, not the actual size of the vent hole, which I agree is too small. The gas cap vent tube is almost 3 feet long, which means dirt has to travel that far to reach and block the small gas cap vent hole. Keeping the gas cap vent tube free of dirt would probably prevent 99% of POOGS issues. In addition, my vent gas cap vent tube was rubbing against the rear tire, which shredded the tube and provided the material to block the gas cap vent tube. I relocated the gas cap vent tube to exit along side the coolant overflow, away from anything that it would rub against. Also, I plan to flush the line once a year and I'm willing to wager that it is unlikely that I'll experience the POOGS issue in the future.
 
1 - 20 of 35 Posts
Top