Gas flow problem - Need advice **Solved**

[Bullgoose]

Coming back from a lunch ride on Memorial Day, bike started running rough with 80 miles on the odometer. Flipped to reserve (pingel petcock), but kept running rough till, eventually, it just stopped. Sat there for a few minutes and the bike started up, but still running rough. Made it a gas station and filled up. No worries for the next 25 miles home.
Today, I rode up the Austin (same tank of gas) and she started running rough at 121 miles (that's more like it). When I went to reserve, bike kept running rough and died as i pulled into the gas station. Put in 4.25 gal., so I still had a gal. in tank. ???
I'm mystified... and I'm hoping to leave Sat. for Minn. & Mich.
Ideas are welcomed!

[JC]

From personal experience  

Sounds like another case of partial fuel starvation caused by:
1. Quick disconnect
2. Dan-marc or similar fuel valve
3. Aftermarket fuel filter
4. Fuel line too long or routed uphill
5. Anything else that may reduce fuel flow when the tank is less than halfway full because it is still a gravity fed system
7. Any combination of the above

The warmer the day and the emptier the tank, the sooner it appears.

6 carbs = one very thirsty engine that requires all the fuel that the stock system can supply, and any modification that may restrict the fuel flow even slightly can result in the problem you describe.

I'm sure there are other opinions out there, but I believe that you will find something in the list is the root of your problem. I take this from my own experience, and having to go back and undo any modification I thought I would have benefited from. I'm all stock again and she runs like a scalded ape to the end of the reserve.

[Slammer]

make sure your vent hose isn't plugged. dirt dobbers love the bottom of the hose. also check that your petcock diaphram hasn't came apart. find the drawing of the petcock and make sure the plastic disc hasn't popped off of the diaphram.

Slammer

[Bullgoose]

Thnx JC.
Don't have a quick-disconnect or Dan-Marc. Do have a fuel filter, but it looked totally clear to me. I had a problem about a 1 1/2 yrs. ago with similar symptoms. Turned out my "new" fuel line was about 1/4" too long. Everything has been working fine till last Mon. Even reserve had been working fine. WUWT?? ???

Don't have stock petcock. Installed a pingel about 1 1/2 yrs. ago. No probs till now.

[JaysGone]

Sounds like the symptoms of a clogged vent.
This can and has happened on my R*.
My vent line on the front of the tank was pinched.
Of course with the Valk at least on mine its just free hanging down to the ground.
If you pop the gas cap when its doing this, the motor then runs smoothly and it goes away.
Then its 100% a venting problem.

[Bullgoose]

Good suggestion. I'll check the vent line and, if it happens again, I'll pop the gas cap and see if that corrects the problem.

[T.P.]

Gunked up petcock screen, run a whole can of Sea Foam to a full tank.

[Chattanooga Mark]

Could you have some water in the tank as well? All the gas I can buy around here has ethanol in it which is whyI often put gas line anti freeze in my tank along with some SeaFoam. I'm trying to reduce the amount of water in the tank as much as possible.

All the best,

Mark

[Disco]

Hey Greg,

That sounds like the symptoms I had in SD, WY, and MT with what proved to be a kinked vent line.  I had had the tank off the previous week chasing a J&M/GPS configuration problem (you've had your tank off recently, right?) and didn't pull the line taut after reassembly.  The weird thing was that, after reassembly, I rode it several hundred miles the next few days before riding almost 1100 miles on a SS1000 and had no problems at all.  Thankfully, they showed up the day after the Iron Butt. 

Like Jay says, put your spare key in the gas cap and go for a test ride.   

DFG

[Bullgoose]

Well, I pulled the tank today and the vent line wasn't kinked nor was it plugged up, but it definitely seems like there's some crude in the tank. So, I'm gonna pull it again tomorrow and drain & clean the tank and put in a new fuel filter just because. Talked with Gearjammer tonight and he suggested I might have gotten some clear-coat  in the tank when I had it painted, but Greg had the gas filler hole very well taped up so I'm not sure that's the problem. But, if there's anything floating around in there, I "should" be able to see it when I drain it.
Stay tuned.

[Hoser]

Could you have some water in the tank as well? All the gas I can buy around here has ethanol in it which is whyI often put gas line anti freeze in my tank along with some SeaFoam. I'm trying to reduce the amount of water in the tank as much as possible.

All the best,

Mark

Gas antifreeze is alcohol, as is a good portion of the SeaFoam.  The ethanol  fuel is 10% alcohol.  It all absorbs water, don't see how you could have anymore water left. I think the fuel filter is too small, slowing down flow at higher speeds when it needs more fuel.  Hoser

[Bullgoose]

Thnx for the post Hosur, but I don't think that's it... unless it's gone bad recently. I went on a ride out to Big Bend the end of March. I went on a ride with one other guy on a Conours which is a very sweet bike. We left Marathon heading south and for about 40-50 miles we were running 100-120mph with no worries. No gas starving at those speeds. Sure shouldn't be doing it at 65mph. But I'm gonna change out the filter tomorrow just in case it's partially clogged and not visible with eyeball inspection.
Will update.

[Bullgoose]

Update:

Pulled the tank this morning and drained the gas into a 5gal bucket. Gas was clear. No snot in it, BUT there was a spring about 1 1/2" long in the bottom. Weird, but I don't see how the would cause a gas flow problem. Anyway, pulled the petcock and there was a screen on it, but it was completely clean. Still, ran a bunch of carb cleaner through it, inside and out. When I was draining the gas thru the petcock, I put it on reserve and the flow was the same as in the open position. Fired the bike up with the tank off (just the gas in the bowls) and it ran fine. So, I put in a gal. of fresh fuel with some Seafoam and I'm gonna go out and ride and see what happens. BTW, the vent hose is NOT kinked.

No joy! Rode for 6 miles and it started running rough. Flipped to reserve. Kept getting rougher till it died. Sat for a few minutes and it fired up. Got about 100yds. and it died again. Put another gal. in and it ran fine all the way home. Seems like I can't get to the last gal. in the tank, but I drained with it the res. position and there was no flow problem. ???

[JaysGone]

Prior to your current problem.
Since installing the Pingel have you had any reason to use reserve?
If so never mind.........
Just a dumb thought.
Do you still have your OEM petcock?
You might want to try it again.
I dont think it, the pingel has anything to do with not getting the last gallon.
I have no knowledge of the pingel at all.

When you popped the cap to put another gallon in.
Did it make any vacuum type sound??
6 miles shouldnt be a long enough time to cause any vacuum condition anyway Id think.

Just thinking outloud here.
Still sounds like a vacuum problem of some sort.

[Bullgoose]

Yeah, I've used the reserve a bunch of times since installing the pingel and haven't had a problem till last Mon. Since then, it seems to be happening every time, except I just ran into town with the petcock in the reserve position and no worries. It's just when I get down to the last 1gal. or 1 1/2 gal. that it starts choking.
Don't know what you mean by a vac prob cuz the pingel is manual, no vac. line.
Thnx again.

[wild6]

Don't know what you mean by a vac prob cuz the pingel is manual, no vac. line.

I think he meant a vacuum condition caused by a plugged vent line.

Anyway, sounds like when head pressure drops (low tank level) you have this condition.  Have you changed out/removed the filter yet?

Edit: Also, have you tried blowing into the vent line to see if it's clogged in the tank? (You mentioned that you had it painted)

[Bullgoose]

Yeah, I blew into the vent line a coupla times. No blockage. I bought a new fuel filter this morning, but couldn't install it without pulling the air box. Not willing to do that yet. If I end up having a lot of problems on my way the Mich., I'll then pull everything and install the new fuel filter. But,
Question: how could the fuel filter be a problem if it works fine, even at 100+mph, till I get to the last 1gal., and then choke?
Not a great way to start a long trip, eh?!

[JaysGone]

All I meant was it still seems<symptoms> like a vacuum problem.
Im aware the pingel has no need for vacuum.
Ive had similar problems with other bikes in the past.
This one not a clue actually.
I dont know the Valk well enough yet.
But a fuel tanks a fuel tank.
Usually.

Good luck on the trip and ride safe........

[T.P.]

HA !  You have paint over spray inside your tank,  ask Wizzard and GEARJAMMER  about the issue.

your pingle pickup screen is clogged I bet.   T.P.

[Bullgoose]

Naw TP. You have to read the whole post! Talked to Bobby a long time last night. No crap in my gas or my screen. I'll let you take a look a in a coupla days, if you so desire.
Aloha!!

[T.P.]

OK read the posting about talking to bobby

[R J]

From your description of the problem, some where in the routing of your gas line it has a low spot and when the gas tank gets to a certain level it doesn't have enough umph to push the gas back up that little rise.

If you go changing the route of the gas line by adding this or that, make damn sure it is always on the downhill, no rises back up even of the slightest.

[Bullgoose]

OK! Problem solved!!
For those of you who suggested the fuel filter (and I came to that conclusion after riding 1000m), we were 1/2 right. Turns out that when I pulled the gas tank and air box memorial day weekend, when I hook up the fuel line again, the fuel filter got hung up on a metal cross piece under the air box. It seemed fine when I was tightening the hose clamp, but when i dropped the tank and bolted it down it kinked the line, but not enough to notice. Riding locally, no symptoms. On a longer ride, when the hose would heat up, then it would kink more and starve the bike for fuel. Discovered this when installing the new filter.
At any rate, I road from Sioux Falls to TP's house in Mn. and a sweet ride it was.
Thnx for all your suggestions!