Gas Tank V’s Auxiliary Fuel Tank to tune Carbs

[BassCliff]

Hi,

same or above, but would it matter if it was really high ? I was just thinking it would/could cause excess pressure, no ?

If it was a large amount of fuel some 20 or 30 feet in the air then it might make a difference. But my IV bottle system is usually about a foot or so higher than where the fuel tank would be and I have no problem with carb sync'ing.




Thank you for your indulgence,

BassCliff

[RobG1970]

LOL Its actually about 15 feet in the air... I took pics tonight but didnt have the time to download the yet ..lol

Hi,



If it was a large amount of fuel some 20 or 30 feet in the air then it might make a difference. But my IV bottle system is usually about a foot or so higher than where the fuel tank would be and I have no problem with carb sync'ing.




Thank you for your indulgence,

BassCliff

[RobG1970]

I may be being a bit blonde but.....

And there are no stupid questions, only stupid answers...

What is re lashing the valves? Setting the valve clearance

Excuse my ignorance.
X

Valve lash is setting the valves

[Steve]

Steve, what's the importance of the same height? isn't the amount of fuel regulated by the floats making the height irrelevant? just wanting to make sure I'm not doing another crazy mistake.

Until Steve answers, I will through in my thought, if I remember from my days in high school....

if it's higher it will have greater pressure pushing it through the feed tube, could cause an overflow situation

I think

but I have been known to be wrong

You are quite right, Mr. GateKeeper.

Yes, the floats are designed to stop fuel flow, but stop and think for a moment what would happen if you raised the fuel pressure that the floats are trying to hold back.

Not sure how much of a difference it will make by being a few inches off, but why push your luck? I try to tune by simulating conditions as close as possible to the way they will be while running.

LOL Its actually about 15 feet in the air... I took pics tonight but didnt have the time to download the yet ..lol

OK, pictures will help, but how, or more importantly, WHY so high?

I just can't imagine climbing something that high to pour a bit of gasoline in, when it is so EASY to make something that will hang on the handlebars or sit on the frame rail over the airbox/battery area.

Personally, I use a gallon-size oil jug that has a hole drilled in the cap. Because of the possibility of leaking where the hose goes through, I CAN NOT RECOMMEND THIS METHOD, but it works for me. Also, by keeping the jug no more than half full, I can rotate it to turn the gas flow ON or OFF.

Here is the jug:



Here, it is turned OFF:



Here, it is turned ON:



OK, you don't have to be real sharp to notice that there is also a gas tank in the picture.
These pictures were not taken during a tuning session, they were taken during a previous discussion about a temporary tank, so I just removed the seat and set the temp tank on the frame.

.

[tas850g]

Steve, do you have pics on how you seal the hole with the hose so it does not leak?

[Steve]

Steve, do you have pics on how you seal the hole with the hose so it does not leak?

Sorry, no pictures of the current setup, be here is a description.

In the original setup, I merely drilled a hole in the cap that was slightly smaller than the (new, supple) plastic tubing, then shoved the tubing through.
That worked for the first couple of times.

I decided that some sort of gasket was necessary, so I drilled the hole the next size larger, slid in a short piece of thin-wall tubing, then slid my gas line through that, wedging it into place. There is still a possibility of a leak, but it is greatly reduced. Because of that possibility, I hesitate to recommend using this setup, but it does work for me. Just please be aware of that possibility of a leak that might show up any time you turn the tank over (turning it ON or OFF), watch for it, deal with it if necessary.

.

[RobG1970]

OK, pictures will help, but how, or more importantly, WHY so high?

I just can't imagine climbing something that high to pour a bit of gasoline in, when it is so EASY to make something that will hang on the handlebars or sit on the frame rail over the airbox/battery area.

LOL.. I have it on a pulley system to raise and lower it out of my way or to fill it… when not in use, I just remove the hose from the bike and raise it up. LOL

[RobG1970]

OK, pictures will help, but how, or more importantly, WHY so high?

I just can't imagine climbing something that high to pour a bit of gasoline in, when it is so EASY to make something that will hang on the handlebars or sit on the frame rail over the airbox/battery area.

LOL.. I have it on a pulley system to raise and lower it out of my way or to file it… when not in use, I just remove the hose from the bike and raise it up. LOL

Now Lowered...LOL

[MisterCinders]

Sorry, no pictures of the current setup, be here is a description.

In the original setup, I merely drilled a hole in the cap that was slightly smaller than the (new, supple) plastic tubing, then shoved the tubing through.
That worked for the first couple of times.

I decided that some sort of gasket was necessary, so I drilled the hole the next size larger, slid in a short piece of thin-wall tubing, then slid my gas line through that, wedging it into place. There is still a possibility of a leak, but it is greatly reduced. Because of that possibility, I hesitate to recommend using this setup, but it does work for me. Just please be aware of that possibility of a leak that might show up any time you turn the tank over (turning it ON or OFF), watch for it, deal with it if necessary.

.

I have many of those Rotella jugs, but the sealing issue always frustrates me.

When I have tried the bottle/tube method with an old 1/2 liter water bottle, I also had problems with venting, because the bottle would collapse as fuel flows, creates a vacuum, etc. How do you vent that Rotella bottle, or is that a non-issue in your experience?

[spyug]

The I/v Mr. GK displayed is actually mine and I've used it that way for 7 or 8 years now with no issues. The hose connects to a piece of brass tube through the cap that its Epoxy puttied in place and coated with automotive type Goop which is rated for gasoline.

One thing I would definitely stress is that there be an inline fuel filter added as I found recently that gas from the pumps is not always free of "floaters" as this pic will show:


The filter in the tank's petcock would usually filter this out so if you don't want to rebuild carb's again, its a bit of cheap insurance.

So show us what you come up with.

Cheers,
Spyug

[Steve]

Now Lowered...LOL

Even though it is "lowered", I would drop it yet another foot, to get it closer to stock height.

How do you vent that Rotella bottle, or is that a non-issue in your experience?

No venting. The way I look at it, the less gas you put in, the more air will still be in there. With a greater volume of air, it will take longer to develop sufficient vacuum to impede flow. Add that to the fact that you don't really draw that much gas from the gallon-size jug, I have never found venting to be a problem. I usually start with about a quart of gas, but never more than a half-gallon.

.

[koolaid_kid]

I went to my local auto parts and got a radiator overflow bottle. Has a cap and 3 nipples. $10. I cut one to place the fuel hose and 1 for a vent. When I am not using it, I place the hose over the vent and store it during the tuning process. Sealing is not a problem, since it was designed for a hose to be attached.
When I am done, I just pour the remainder in the mower gas can and store it away.

[RobG1970]

[QUOTE=Steve;1669927]Even though it is "lowered", I would drop it yet another foot, to get it closer to stock height.

I actual only lower it to fill it and open the petcock, why would it matter if it's gravity feed to be lower to the bike????

[koolaid_kid]

The pressure on the needle and seat increases as your raise the tank. Fluid pressure of a column of a fluid can be calculated, but is beyond this discussion. Suffice to say that the taller the column, the higher the pressure.
Many issues can occur because of this added pressure, and you really don't want to do that.
Take that tank and hang it from your left hand grip. This will best emulate the natural pressure of an actual fuel tank.

[RobG1970]

The pressure on the needle and seat increases as your raise the tank. Fluid pressure of a column of a fluid can be calculated, but is beyond this discussion. Suffice to say that the taller the column, the higher the pressure.
Many issues can occur because of this added pressure, and you really don't want to do that.
Take that tank and hang it from your left hand grip. This will best emulate the natural pressure of an actual fuel tank.

Okok- now things are making sence, how much slack in the hose if any???