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Scooters - 125 to 300 => Super 8 150 => Topic started by: Eugene on January 19, 2016, 12:56:20 AM

Title: Dual-fuel tank
Post by: Eugene on January 19, 2016, 12:56:20 AM
Hi guys, I would just like to ask if there is such thing as one way fuel valve?

We have successfully installed an additional 5 liter fuel tank on my 150 and I tested it for 2 days. What I've observed is the fuel from my under tank flowed up to my upper tank, hence, it over spilled after using it for 2 days.

Any thoughts? Thanks!
Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 19, 2016, 07:18:45 AM
Maybe we have a translator problem here because I have trouble understanding how fuel can flow from an under tank into an upper tank. I am reading "under" to mean lower and "upper" to mean higher.

Karl
Title: Re: Dual-fuel tank
Post by: Eugene on January 19, 2016, 08:24:50 AM
Hi Karl,

Yes, you are right, under tank means lower tank and upper means the higher tank. Sorry for that.

I'm puzzled too how the fuel flowed up to the higher tank. Last 2 nights ago, I filled both with half tank just to check if there would be problem. Last night when I checked on it, there were overflowed gas in my utility box, when I peeked inside the lower tank, it's almost empty and the higher tank is full.

Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 19, 2016, 04:11:14 PM
I will bet your lower tank has a non-vented cap or no vent whatsoever.

Karl
Title: Re: Dual-fuel tank
Post by: de dee on January 19, 2016, 05:14:38 PM
I will bet your lower tank has a non-vented cap or no vent whatsoever.

Karl
    and the lower tank has a heat source under it,  close to the engine,

Title: Re: Dual-fuel tank
Post by: de dee on January 19, 2016, 11:17:41 PM
there is a reserve switch on my tractor one tank or the other it is a sears garden tractor pgt 9000  parts are available at sears parts department
Title: Re: Dual-fuel tank
Post by: Eugene on January 20, 2016, 12:45:38 AM
I will bet your lower tank has a non-vented cap or no vent whatsoever.

Karl


HI Karl,

So what you are suggesting is to change my tank cap to a vented one?

We're planning to put a switch so that I can close the vacuum from the fuel pump. I'll be using the higher tank first and when it goes empty, that's the time I'll be switching on the vacuum to trigger the fuel pump.

Any thoughts, guys? 
Title: Re: Dual-fuel tank
Post by: Eugene on January 20, 2016, 12:47:34 AM
there is a reserve switch on my tractor one tank or the other it is a sears garden tractor pgt 9000  parts are available at sears parts department

We don't have Sears parts department here in our place.
Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 20, 2016, 05:31:27 PM
A vented cap may solve the problem of undesired transfer. I visualize your system as the fuel path from each tank goes to a "T" and then to the vacuum valve and then to the carburetor. The pressure in the auxiliary tank (with no vent to atmosphere) pushes the fuel into the main tank. Am I on track, so far?

You have a great idea to extend the limited range of your scoot. It is also a great idea for several models including the People GTi300 which will go 100 miles with a TINY reserve. It is a great cruiser but with about 2.4 gallons is limiting options for refueling thus requires a red plastic gas can strapped on somewhere. All kinds of specialty shops make aux tanks but it is up to the installer to make it work. You are, so far the pioneer in developing a usable system.

Most aircraft have two or more fuel tanks plus a system of selecting tanks to feed the engine(s). Each tank is vented independently. On, off and crossfeed is a manual function of the pilot. The basis of these systems is simplicity.

Karl
Title: Re: Dual-fuel tank
Post by: AMAC1680 on January 21, 2016, 03:57:58 PM
I don't screw around when it comes to gas and spark. I've used these tanks for long haul and love them. Not cheap but gets the job done right.

http://shop.spunaluminumgastanks.com/Motorcycle-Tour-Tanks_c18.htm (http://shop.spunaluminumgastanks.com/Motorcycle-Tour-Tanks_c18.htm)

AMAC
Title: Re: Dual-fuel tank
Post by: Eugene on January 22, 2016, 01:16:38 AM
A vented cap may solve the problem of undesired transfer. I visualize your system as the fuel path from each tank goes to a "T" and then to the vacuum valve and then to the carburetor. The pressure in the auxiliary tank (with no vent to atmosphere) pushes the fuel into the main tank. Am I on track, so far?

You have a great idea to extend the limited range of your scoot. It is also a great idea for several models including the People GTi300 which will go 100 miles with a TINY reserve. It is a great cruiser but with about 2.4 gallons is limiting options for refueling thus requires a red plastic gas can strapped on somewhere. All kinds of specialty shops make aux tanks but it is up to the installer to make it work. You are, so far the pioneer in developing a usable system.

Most aircraft have two or more fuel tanks plus a system of selecting tanks to feed the engine(s). Each tank is vented independently. On, off and crossfeed is a manual function of the pilot. The basis of these systems is simplicity.

Karl

Hi Karl,

Thank you!

Yes, you are right! The upper and the lower tank meet at a "T". What we did now is we installed an on-off fuel switch but instead of putting it in the fuel hose, we installed it on the vacuum's breather hose. In that way, the fuel pump's vacuum won't be working if the breather is shut. I'll be testing the system for a long ride the day after tomorrow. I'll be having them full tank and we'll see how it goes. I'll be sharing some pics later for others to visually understand what we're talking about, Karl.

I haven't found any vented fuel cap as of the moment.

Thank you for your time!
Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 22, 2016, 03:23:57 PM
Super 8 150 Owner's Manual shows fuel cap under the seat so the "high" mounted tank will be gravity feed to the carburetor, therefore, no fuel pump. I say this because I did not understand what you said.

Karl
Title: Re: Dual-fuel tank
Post by: Eugene on January 23, 2016, 02:50:59 PM
Super 8 150 Owner's Manual shows fuel cap under the seat so the "high" mounted tank will be gravity feed to the carburetor, therefore, no fuel pump. I say this because I did not understand what you said.

Karl

That's right. Sorry for my crooked grammar.
Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 23, 2016, 06:44:59 PM
No need to apologize for "crooked grammar" since many of us cannot understand each other! It is a process of question and answer to establish clarity. I would post a diagram if I were smart like some of these others.

Karl
Title: Re: Dual-fuel tank
Post by: Eugene on January 27, 2016, 01:04:41 PM
Hi guys, I've tested the functionality of our dual-tank project on a long distance drive and I can say that it was a success!

Here are some pics of the system we've made:

(http://imagizer.imageshack.us/v2/150x100q90/912/0gKJoR.jpg) (https://imageshack.com/i/pc0gKJoRj)
This is where we put the gas tank.

(http://imagizer.imageshack.us/v2/150x100q90/633/4Ym8T7.jpg) (https://imageshack.com/i/hl4Ym8T7j)
This is the fuel switch we installed

(http://imagizer.imageshack.us/v2/150x100q90/907/QgysdQ.jpg) (https://imageshack.com/i/p7QgysdQj)
This is what it looks like inside my utility box

(http://imagizer.imageshack.us/v2/150x100q90/903/mt6Lpu.jpg) (https://imageshack.com/i/p3mt6Lpuj)
This is the "T" connection which links the two gas tank
Title: Re: Dual-fuel tank
Post by: CROSSBOLT on January 27, 2016, 04:53:09 PM
How do you fill the lower tank with all the plastic back? How does the fuel get from lower tank to carburetor?

Karl
Title: Re: Dual-fuel tank
Post by: Eugene on January 27, 2016, 06:03:22 PM
How do you fill the lower tank with all the plastic back? How does the fuel get from lower tank to carburetor?

Karl


Hi Karl,

I have removed all the fairings already because of my previous crash. The only fairings left is the ones under the seat. The fuel goes up via fuel pump. The fuel switch I installed is not connected to the fuel hose, it is the breather hose instead to switch off the fuel pump due to my previous problem.