Half Tank Lean Issue

[byron]

I keep hearing and seeing things that talk about a half tank lean issue with the stock fuel tank in the Savage's. Is there any truth to this?? I am trying to get the perfect tune, and if the stock tank does this then I would like to fix it. What makes the stock tank do this? Is it the location (under the carb) or is it a design flaw with the tank itself? I see a few people change them to sit between the frames, is it just something cool to do, or does it give you a consistant tune?

 

[beason]

from what i have read its the tank, the way it has that step in there changes the pressure of the fuel because it changes the surface area once it passes that spot. a different tank would fix it, or a header tank like rolex runs. I've heard a nice long set of fuel lines will help alot to.

 

[HeartBreak]

from what i have read its the tank, the way it has that step in there changes the pressure of the fuel because it changes the surface area once it passes that spot. a different tank would fix it, or a header tank like rolex displays. I've heard a nice long set of fuel lines will help alot to.

Post fixed .

 

[ohmygahitscoby]

I've also heard that doing the mid-tank mod also removes that. But the downside is that it you would have to buy new things and you would lose some of your runtime on some tanks.

 

[Scrogg]

It is the tank no doubt. I ahve done quite a few mid-tank mods on Savages, every one tuned easier and more consistently afterwards. I'll have to take some pics of the Savvy I have now to share. It is not a midtank but I installed a Mugen MBX5T 160cc fuel tank in the stock location with some minor mods. This is on an extended chassis, it will not fit on a regular length Savage.
Here's my old Savvy, never should have got rid of this one.
It had a Hellfire 150cc tank in it. Runtime was really close to stock because you did not need to run the engine overly rich to compensate for the HTL.

Crappy pics I know, sorry. It was an old camera with a bad operator.

 

[rossb]

The uniflow mod worked wonders for my truck. I have been running the mod for about 5 years now. Pics here.

 

[byron]

That's a new one...I have not seen that one before? Did it get rid of the 1/2 tank lean issue? Is that still the stock tank? Did you actually cut the tank??

 

[rossb]

My tank is stock. It is not cut, I'm not even sure what that means. This mod has been around for years and it solved my leaning issue. This page explains the physics behind it:

http://www.fraserker.com/heli/uniflow/how_uniflow_works.htm

The only drawback is when the engine is off the tank will no longer be able to vent to air through the pipe. If the truck sits with fuel in the tank the fuel may flow out the pipe or into the carb (flooding it out). When my truck sits I usually blow the fuel back into my fuel bottle by sticking the fuel output line in the fuel bottle and blowing into the exhaust pressure line. You can also allow the tank to vent by propping the fuel cap open slightly with the zip tie most people have attached to the tank cap.

 

[byron]

In your pictures, there is some grey stuff that looks like it goes around the tank, it looks like epoxy, what is that for?

 

[rossb]

That tank split at the seam and it was leaking so I used JB Weld to fix it.

I've since replaced the tank.

 

[Rolex]

Post fixed .

LMFAO!!! Now where did I leave my ban stick?

 

[byron]

I thought I was seeing things that were not actually there....I need to go to bed eariler