High MPG bike Phase 2 fuel system
The Fuel Follies - This happened from Monday October 8th through early January 2008.

 Sunday October 14th update - Fuel Fuel Fuel.

The first lesson I learned at the end of phase one was that testing mpg accurately over and over  wont be easy. 

  • I need to measure how much fuel is going into the tank before each ride and know that that is all that is in there.
  • I need to measure how much fuel is left after a ride. That means getting it back out somehow.   
  • I can not account for gas station equipment calibration.   
  • Fuel, like any other substance changes volume when temperatures change. 
  • The stock tank has low points that never get used until the bike is tilted  so I can not account for how much is stuck in there. 

Add all that up and it gets hard to accurately judge how much fuel you really used.  When you consider that I have as many as 100 test rides to complete for phase two this becomes a big problem.  What I needed was a better gas tank. I also need a way to get fuel back out easily and an accurate means of measuring all that fuel. Thus begins the Fuel Follies.

I figured I need about a gallon, maybe a little less, for test runs. Around 5-6 inch diameter and 10-11 inches long would fit the bike ok. I have enough aluminum around to build one but don’t want to spend loads of time on this. Keep in mind that this is temporary since a new tank will be built to fit in the new frame and fairing for phase 3.

I thought about hacking up a fire extinguishers and welding on an end cap but they are too expensive. I looked at the scrap yard but found nothing. I finally began marking up a piece of 3/16ths to cut out and fold up but didn’t get to cutting since it was getting late.

Saturday I was on my way to Home Depot to get some stuff for the bathroom I am re-doing, nothing but excitement in the life of a home owner!.  The answer hit me like a freight train. I couldn't believe I had missed it. I blew past Home Depot and went to pick up my new gas tank. 

It is bigger than I hoped at 5 liters and  I still have to empty it of it's original contents, I worked on that this weekend but have a long ways to go.  my neighbor has agreed to help me on that task but both of our wives may squawk if we work on it too much.  I will need to weld on a tank outlet and weld an inlet pipe on and close the hole in the center before it is done but that should not be a big problem. I may even leave the word Heineken on it! 

5 liter = 1.32 gallon US, calculated by http://www.onlineconversion.com/volume.htm.

More fuel things worked out

I still need to drain the fuel after each run to see how much is left over.  After some snooping I found and ordered a valve meant for experimental aircraft. 


 It is a three port valve meant to direct fuel from one of two tanks to the engine. In this case I will plum the gas tank outlet to the common side with one side going to the carb and the other to a drain line. I will drain the tank to the valve to get it to a know low point prior to filling it each time, this accounts for evaporation between test runs.

Next I put in a known amount of gas and go for a test ride. When I get back I drain the remaining fuel into my mad scientist starter kit, see below, and take a reading. That should settle my fuel measurement issue.

The volumetric issue means I need to supply my own fuel. I will use a regular gas can to bring it home from the gas station. I will pick a reasonable and repeatable fuel temp and will let the tank normalize to that temp every time before measuring out the fuel. I will also need to normalize the temp when taking the after ride measurements listed above.

I will test the variation in volume and make a chart at some point so I can adapt for temperature changes any time.

I ordered some nifty glass scientific cylinders and flasks from Novatech. I now have a mad scientist starter kit that would make Bill Nye proud. I put links  for them in the links page in case you think they are too cool not to have your own. Ummmm, yaaa!. 

I will fill the flasks to the 1000mL mark and fill the tank with them prior to each ride. After each ride I will drain the tank into the flasks and use the cylinders to get an accurate read on how much is left.

Viola, Fuel measurement is now solved. All I need to do is empty the mini keg, make my new fuel tank and hope that damm carb is working.  Now where did I put my beer Stein


Sunday, 11/4 - Metal working 101 again

Tank is all drilled and all bits have been cut out and readied to weld into place. The filler cap is the top of a 1 qt. mineral spirits container from Ace Hardware. I cut another piece from the same can for the end cap of the tank but that may change.

Before I weld anything I am going to practice on some scrap since I don't know what alloys were used and I don't know what temp and rod will work best. That is next weeks project.

I needed to flatten the area where the fuel outlet would be attached so I rigged up a bolt with a wire on it. I fed the wire through the end hole and up through the fuel outlet hole. That allowed me to pull the wire, and eventualy the bolt, through the hole into place. A long wrench through the end hole held the bolt while I cranked a nut down on it. This squashed the surrounding aluminum can area nice and flat. I even heated it up and worked it into a low point while the bolt was in there


Tuesday, 11/6 - Here's beer in your face!

I am one lucky guy. I was working up some scrap bits of tank to practice welding on, the local package store was good enough to give me some returned Heineken Draft Keg empties to use. I need to cut one up to practice welding on before tackling the actual tank.  The first mini Keg was one I had finished myself. I emptied it completely and vented it before working on the keg.  I am thorough like that when it comes to beer!

It never occured to me that someone would have not drained every last drop out of a keg of beer. Perhaps that is residual affect of my partying days but it never occured to me just the same.  That proved to be problem #1.

I also never though about the fact that there might still be some pressure left behind that someone had not bled off. That was something I simply overlooked. It turns out that Heineken has been very generous with their supply of Nitrogen in these little kegs. That was problem #2.

For a bit of added affect this keg proved to have been sitting around for a while before I got it causing the beer to be, um, very unpleasantly old. That is Problem #3

When I drilled into the center to cut out the tap area the drill, just as it breached the valve I was drilling through, wedged itself to the side. When it did that it opened the valve all the way.  Unfortunately this is where Problems #1,  #2 and #3 come into play.

Wedging the drill in there had much the same affect as holding your thumb over the end of the garden hose. You would be amazed at how far you could shoot beer from one of those kegs under the right circumstances, which I had just evidently definned. I narrowly escaped having to clean very old beer from the shop ceiling and shelves.

Perhaps now is a good time to state that I rarely have any good luck and today proved much the same.  While escaping the hosing down of my shop with old rancid beer may sound good, you need to picture how that happened. I was holding the keg between my feet to keep it from spinning. I was bent at the waist holding the drill and, and here lies the truly unlucky part, staring straight down at the drill. I was what stood between the rocket powered stale beer and the ceiling. In other words I got it point blank in the face and chest when it let go. Next time I must remember to vent that dam tank!

So I now have a bucket of scraps to settle how best to weld the new tank together. I also have torches capable of a variety of temps and a number of Aluminum welding, soldering and brazing rods.  Now I will put flame to it and figure out what I can and cant do with the Draft Keg material.

Sunday, 12/23 - Why are wives so intolerant of motorcycles in the house?

I have again managed to get a few things done. The tank is completed.  The top of a  paint thinner can, and it's cap,  formed the fuel filler area saving me some time. 

It turned out that a metal solder was strong enough and easiest to keep the tank from warping.  One person has stated some concern for this method as they believe the metal working solder I used will not hold to the aluminum and I do trust his judgement but the tank is made. Time will tell.

I have decided to put the tank over the main tube to allow me to cut into the seating area some.  Remember that this is the ugly experimental phase so looks do not count here. I need the tank high enough to allow the three way valve to be between it and the carb withut causing the fuel line to loop. That would make the bike stop running. To deal with this I made a steel cradle to hold the tank.

Unfortunatley My wife has decided that the bike should not stay in the family room where it currently resides.  She believes that is the place to entertain all the relatives who are coming over Christmas and New Years Eves. The problem is there is more than a foot of snow on the ground making it complicated to get the bike out. I guess I have this weekends work cut out for me. On the up side I will be able to weld the tank support to the frame as soon as I get it out there.  Mata Ne!

Sunday, 12/30/2007 - The tank is mounted!

Over the Holiday break I managed to Finish mounting the tank. The Tank is mounted in the new cradle and sits high enough to allow the three way valve to be installed without creating a low spot in the fuel system. Yay!

The last part of the fuel follies was completed as part of the phase 2 electrical project. I needed a place to mount the three way valve.  When the Electrical service panels were mounted I saw the perfect place. Not only did this give me a shock mounted place for the valve but I know have a nice place to put valve possition labels, hey, I forget stuff a lot so I need labels. A few bits of fuel line and all is well. Boy, that took a lot longer than I thought it would. 


Post Script;

It figures after all this that I would find the perfect tank was readily available, and at a good price. If the keg tank fails durring the testing this summer I will just order one of these beuties for $119.00 and toss it in the same brackets that are there now. It even comes with ready made brackets.  http://www.tourtank.com/tourtanks.html