The trip that didn't happen - Quick Disconnect problems

[pBrain]

I just wanted to let you know of an issue I had with the quick release (with filter) on my Valkyrie.  I was experiencing issues where after a while, I the bike would choke like it was out of fuel and then come back and then start growling again.  This happened 4 times today while on my way to visit family.

Each time I looked at vacuum lines and tested them to make sure there was vacuum.  Looked for vacuum leaks, fuels leaks, etc.  Tested the power to the Dan Marc fuel cutoff.  Tested the battery and even topped off the tank.

Then  I decided to do what I have learned to do when I can find the solution, find the last thing I installed, remove it and see if the problem persists. 

I went ahead and removed the quick disconnect and reconnected the petcock directly to the Dan Marc.  Rode the bike back home without a problem (cancelled the trip in case it was something more serious).

I blew fuel through the filter and was able to get fuel to flow through just fine.  This is what I think the problem is:

I learned way back that the fuel flow on the Valkyrie is highly dependent on gravity.  I believe that the loops in the hoses of the disconnect create a disruption and cause gas to not make it to the engine.

Anyone else has experienced this?  How did they resolve it?

[R J]

Took the damn quick disconnct off and tossed it on the shelf where it still lays today.

[BF]

I put one on.  The bike acted like it was running out of gas at about 80 miles.....every time. 

Don't know what it was about the 80 mile mark, but it kept doing it right at about 80 miles.  Kept having to switch to reserve and get to a gas station to top it off. 

It would run just fine after that....untill it hit about 80 miles again.....then it would act like it was starving for fuel again.   

Searched some posts on here and figured out it had to be that quick disconnect kit thingy I'd put on.

I had to tie it up to where the the loop is laying flat under the tank instead of just hangin down doing the loop de loop.

Works fine now.   

However, it's going in the garbage the next time I take the tank off. 

[Grandpot]

I had the same problem.  Took it off.  No problem now.

[Michvalk]

Just another case of "I'll keep fixin' it til it's broke" Many have had problems with the quick disconnects, and the extra filters as well. I understand the logic of adding those things, but, I only had my tank off twice in 40,000 miles. Once to clean the carbs when I first got it,(previous owner left it set for three years) and once near 40,000 miles to change the air filter.

[John Schmidt]

I don't have a quick disconnect, but do have a Pingel petcock in line with an external filter and Dan Marc shut off. Many have had a similar problem with that setup, I never have because everything in the line runs downhill from the petcock. With the QD in the system with its extra loops in it, it doesn't always run downhill. And once the fuel level drops a bit there's not enough weight pressing down on the fuel in the line to overcome the sag or low spots and causes fuel starvation. I've had my setup in place for about seven years with not the first issue....but it must run downhill all the way, can't be level.....DOWNHILL.

[Jess from VA]

I had two quick disconnects for my bikes.  Before I used them, I read so many bad stories about them, they are still in the parts bin.     

[Grumpy]

I put one on my IS a while back, after it left me on the side of the road twice, I removed it and threw it as far as I could. Waste on time and money.

[saddlesore]

Yup, had one too.  Not quick and leaked. Tossed mine too.

[Toledo Mark]

Same issue here.  Took it off and back to normal.

[Willow]

There are many that use the quick disconnect with success and many that don't.  If the tubes are attached in such a way that there is any uphill it seems to regularly result in failure.

[Pappy!]

BF - After 80 miles there wasn't enough gasoline In the tank to supply the needed head pressure to flow through the filter any longer.

[pBrain]

Great explanation on the issue from Rich at http://www.valkparts.com

The Valkyrie has a heat issue.  It wasn’t originally much of an issue, because fuel had no ethanol in it.  Now that ethanol is in it, the vapor pressure is increased at lower temperature.  The Valkyrie  has its carbs hanging over the crankcase.  The crankcase is hottest in the middle (reaches oil temperature near 220F) but not quite as hot just over the barrels, because they have a water jacket.  There it only gets up to 185F.  The carbs pick up this heat, transfer it to the fuel, and create a big bubble that tries to go back to the fuel tank, because the float valves are shut when the carbs are full of fuel.  (You are in deep doo doo when the carb temp gets up to 170F.  Feel a carb bowl with your hand – it hurts at 165F-175F. ) When you are using the stock fuel hose layout, it has good bubble handling.  Lots of bubble flies back to the fuel tank, and lots of gas fights its way past the bubble to feed the carbs.  With the disconnect, the bubble has more of a problem getting back to the fuel tank.
 
The experts you are taking your clues from suggest going back to the original fuel hose setup and letting the bubble and fuel fight it out.  This is because they do not believe in the bubble.  It all boils down to this: Belief in the fuel bubble or no belief in the fuel bubble.
 
Red Eye has a solution for the bubble, and it is called a heat shield.  It is a thick cover of silicone rubber that goes on top of the engine.  It keeps the carbs from heating up so much in the first place.

[MP]

I put one on without a filter.  Rode it a couple thousand miles without any problems on my I/S.  Then, it started starving for fuel about at 1/2 tank or so. Would not even run.

Took it off, and have over 10,000 trouble free miles.

Willow may be right about the flow,, but I kept mine as much downhill as possible.  It was on my sidecar rig, which gets about 17 mpg, so I was REALLY sucking a lot of fuel thru it, probably double what most of you use, so that may have been part of the problem.

MP

[BF]

Great explanation on the issue from Rich at http://www.valkparts.com

The Valkyrie has a heat issue.  It wasn’t originally much of an issue, because fuel had no ethanol in it.  Now that ethanol is in it, the vapor pressure is increased at lower temperature.  The Valkyrie  has its carbs hanging over the crankcase.  The crankcase is hottest in the middle (reaches oil temperature near 220F) but not quite as hot just over the barrels, because they have a water jacket.  There it only gets up to 185F.  The carbs pick up this heat, transfer it to the fuel, and create a big bubble that tries to go back to the fuel tank, because the float valves are shut when the carbs are full of fuel.  (You are in deep doo doo when the carb temp gets up to 170F.  Feel a carb bowl with your hand – it hurts at 165F-175F. ) When you are using the stock fuel hose layout, it has good bubble handling.  Lots of bubble flies back to the fuel tank, and lots of gas fights its way past the bubble to feed the carbs.  With the disconnect, the bubble has more of a problem getting back to the fuel tank.
 
The experts you are taking your clues from suggest going back to the original fuel hose setup and letting the bubble and fuel fight it out.  This is because they do not believe in the bubble.  It all boils down to this: Belief in the fuel bubble or no belief in the fuel bubble.
 
Red Eye has a solution for the bubble, and it is called a heat shield.  It is a thick cover of silicone rubber that goes on top of the engine.  It keeps the carbs from heating up so much in the first place.

So if I read that right, I need to buy his heat shield to make the quick disconnect work properly?

[BonS]

Great explanation on the issue from Rich at http://www.valkparts.com

The Valkyrie has a heat issue.  It wasn’t originally much of an issue, because fuel had no ethanol in it.  Now that ethanol is in it, the vapor pressure is increased at lower temperature.  The Valkyrie  has its carbs hanging over the crankcase.  The crankcase is hottest in the middle (reaches oil temperature near 220F) but not quite as hot just over the barrels, because they have a water jacket.  There it only gets up to 185F.  The carbs pick up this heat, transfer it to the fuel, and create a big bubble that tries to go back to the fuel tank, because the float valves are shut when the carbs are full of fuel.  (You are in deep doo doo when the carb temp gets up to 170F.  Feel a carb bowl with your hand – it hurts at 165F-175F. ) When you are using the stock fuel hose layout, it has good bubble handling.  Lots of bubble flies back to the fuel tank, and lots of gas fights its way past the bubble to feed the carbs.  With the disconnect, the bubble has more of a problem getting back to the fuel tank.
 
The experts you are taking your clues from suggest going back to the original fuel hose setup and letting the bubble and fuel fight it out.  This is because they do not believe in the bubble.  It all boils down to this: Belief in the fuel bubble or no belief in the fuel bubble.
 
Red Eye has a solution for the bubble, and it is called a heat shield.  It is a thick cover of silicone rubber that goes on top of the engine.  It keeps the carbs from heating up so much in the first place.

So if I read that right, I need to buy his heat shield to make the quick disconnect work properly?

Or buy non-oxygenated gas? There are other good reasons for doing so but it sure seems like a lot of hassle for accommodating a quick-disconnect.