Tank/Reserve question

[Napom]

Originally Posted by Cynic

Nappy, I believe you are referring to the fuel lines, not the petcock tubes. Remove your tank petcock and you'll see what I was referring to. The only way to extend the amount of fuel available without replacing the fuel tank with a larger one, or adding an auxillary tank, would be to cut the reserve tube even shorter. If you do this, you'll succeed in adding a couple ounces of fuel availability...as well as potentially allowing more sediment into the filter, thus resulting in more frequent filter changes (a pain in the ass, if you don't believe me, look where the fucker is mounted). So, call it an additional four ounces gained (an optimistic estimate), and at an average of say 40 mpg, you will get an extra 2.5 miles on reserve, and nothing gained on main setting. IMO, not worth the time and trouble to remove the petcock, cut the tube, sand the tube free of burrs and shavings, and re-install the petcock...but, I guess its up to you.

That's why its good to ask first! Thanks!

[HaChayalBoded]

Originally Posted by Napom

So - with this incredibly old post on this seemingly revived thread; If you were to lengthen your reserve tube, that would give you greater overall range - right? Providing you didn't run the reserve dry, you would have the reserve tube gas, + the 4.2 or so of the tank. The same could go for the main fuel tube right? Would this have any effect on the fuel delivery since the fuel would have to be pulled through a greater distance? Then again - how much fuel could you actually increase by adding a couple inches of tube? Would it be worth the extra mile or two (I know if pushing a bike you would say yes).

When riding long distance through populated areas, I generally ride tank to tank - Ride till I hit reserve then find gas. When riding through the boonies, I look for gas every 100 miles or so and fill up even if we just stop to take a leak at 50 miles . . . But was looking to stretch the mileage and after readiing this, thought the tubes may be a cheap way to do that . . . Thoughts?

I think you're not understanding the way the fuel system works. Let me try to explain it. The tubes in the tank, atop the petcock are like straws. Turning the petcock to main has the fuel coming down the taller straw, once the fuel level drops below the top of the straw you have to switch to reserve which has the gas coming in at a lower point (because the reserve tube or straw is shorter).

So to increase the amount of usable fuel you would have to cut down said tube. Next time your bike is on empty you can go ahead and pull the petcock assembly and see how tall those tubes are. Every Sabre is different as they simply cut the tubing there, they don't have a big box of tubes that they just press in.

I need to swap in a Sabre motor into my shadow, you guys are averaging around 10mpg more than I am. I'm at reserve at 120 consistently and I'm just about walking by 150 miles. I'm working on a 7.5g tank for mine, should get me roughly 260 miles.

[Napom]

Originally Posted by HaChayalBoded

I think you're not understanding the way the fuel system works. Let me try to explain it. The tubes in the tank, atop the petcock are like straws. Turning the petcock to main has the fuel coming down the taller straw, once the fuel level drops below the top of the straw you have to switch to reserve which has the gas coming in at a lower point (because the reserve tube or straw is shorter).

So to increase the amount of usable fuel you would have to cut down said tube. Next time your bike is on empty you can go ahead and pull the petcock assembly and see how tall those tubes are. Every Sabre is different as they simply cut the tubing there, they don't have a big box of tubes that they just press in.

I need to swap in a Sabre motor into my shadow, you guys are averaging around 10mpg more than I am. I'm at reserve at 120 consistently and I'm just about walking by 150 miles. I'm working on a 7.5g tank for mine, should get me roughly 260 miles.

Thanks for the info . . . If you get the bigger tank done let us know how . . . I regularly hit reserve during conservative highway miles at 125 miles, for relaxed country cruising I have made it to 142. I estimate my :reserve is good for about 17 miles" We'll see if any of that changes with my Batwing . . .