Under seat fuel tank shortcomings.

[formariz 12,047]

What is the thinking behind under seat tanks having a substantially large section where gas gets trapped and not used? On every tank that I have removed to clean, that area was full of crud and water. Every time you fill an empty tank , new gas is really getting contaminated by the sitting unused gas in that section, particularly if one is bouncing around while using tractor. It was puzzling me why in  a perfectly clean tank I was always finding debris until I started taking them out to flush them properly. Has anyone ever thought of installing another outlet in that area and connect it to the main line? There is probably over 1/2 gallon in that section. I am about to do such modification.

[AMC RULES 37,211]

Now, that's a great idea Cas.  

[KC9KAS 4,744]

@formariz Do it with another shut off valve then just "TEE" the lines together.

 

Maybe  was thinking on the line of the motorcycles that had fuel tanks straddling the frame....But those had a "reserve" on the petcock!

[AMC RULES 37,211]

 Something like this would be nice. 

[clueless 3,270]

Zero turns with two tanks have a three way valve, point the lever to the right for the right tank, point it to the left for the other, middle is closed.

[Chris G 3,361]

That's a great idea

[roadapples 6,983]

 it would be like NASCAR. Flip the switch and one more lap. (or back to the barn) 

[Jake Wilkerson 38]

A three way valve is the way to go and treat the new line as a reserve or “get home” setting. 

Edited January 6, 2019 by asleepz

[Lee1977 7,232]

I looked at my 312-8 I believe that area holds less then a quart. I'm on a hill side and most of that area would splash out once the deeper side goes down.

[formariz 12,047]

52 minutes ago, Lee1977 said:

I looked at my 312-8 I believe that area holds less then a quart. I'm on a hill side and most of that area would splash out once the deeper side goes down.

That is when all the sediment and possibly water will contaminate the rest.

Since I have a few tractors with that tank setup and I am not a real fan of them since gravity is against that whole system, I am going to modify a second one by eliminating that tank and setting a tank on the battery location like the older Cs. I will move battery to the usual position on the bottom which will also allow me to use a larger capacity battery with higher cranking amps rating. Shorter fuel line with gravity in its favor along with a larger battery will make it for a better tractor. I see that I can also fit a larger capacity tank than found on older Cs.I have a few tanks here that will work great.

[Ed Kennell 42,217]

27 minutes ago, formariz said:

 I am going to modify a second one by eliminating that tank and setting a tank on the battery location like the older Cs.

And solve the hard starting problem caused be the fuel leaking back to the tank allowing the fuel pumps lose their prime.

[formariz 12,047]

12 minutes ago, Ed Kennell said:

And solve the hard starting problem caused be the fuel leaking back to the tank allowing the fuel pumps lose their prime.

Yes, however i pretty much fixed that problem before. One by introducing an electric fuel pump, but the easiest and least expensive solution was to install a check valve directly underneath fuel pump. That couple of dollars and 5 minutes of work yielded instant results.

[dells68 7,499]

@formariz said, “I am going to modify a second one by eliminating that tank and setting a tank on the battery location like the older Cs. I will move battery to the usual position on the bottom which will also allow me to use a larger capacity battery with higher cranking amps rating.”

That’s exactly what I did on Emory’s Work Horse and it helped starting tremendously since I got the new carb and have it running good.  Almost instant starting like with an electric pump without the worry of failure with the electric pumps.