Half Lean Is Real!

[Fx]

Heres my experience, I have an Axial .28 all sealed up. I have tested for are leaks 5 times and none at all. I run my Axial .28 hard and it is 220-230 degrees. As soon as it nears the half way mark on the tank it goes from 220-230 all the way to 270-280. No airleaks and it is tuned to perfection, I tune my smoke trails and performance, not temps. I am saying HALF LEAN IS REAL, it may not happen to you but it happens to some of us. It's no myth, it exists. I am going to copy jrstorm's way he fixed it. He used a small header and primed it with a fuel filter/primer. Just figured I would share my thoughts on half lean and put in my 2 cents.

 

[Jeremy]

Whoever said it it didn't exist ? my surefire never really had a problem w/ half tank lean...... but my sts it does so I think different engines react differently to have tank lean.. but a 30* jump in temp seems allot to me

 

[Fx]

I've heard people say it's just a myth, and just wanted to share my experiences.

 

[RangerRock]

Lol with my sts its a major prob......cant stand it either....

 

[Jeremy]

just richen it up a little... problem solved !!!!!

 

[Hoppedup Savage]

or get a header tank, or one of JT's midtank mods, and its ALL solved

 

[gzus11]

thats what i would suggest, although i have not experienced it running either of the four engines i run in the sav.

someone gave an accurate description of the mechanics of the problem, i cannot find it but it is basically due to the fact that the needle jet level of the carb is the at mid level of the tank, so the first half a run fuel is pressure fed and and gravity fed, then the remaining is pressure feed alone, which leads to reduced fuling.

let us know how the header treats you, will you get a clunk with it?

 

[Blazer X]

Pardon my ignorance but what is a header tank? And fx my axial 32 midrange needle was so loose it was screwing itself two or three turns in one tanks time.

 

[Fx]

Thats stinks blazer, replace the o-ring. A header is a small tank tank that you put on the truck and doesn't have the self so there is no half lean. it's basically two tanks but the header delivers the fuel to the engine at a consistent pressure, unlike the savage tank.

Here is jrstorms header.

 

[fmj40]

With that said, is it possible to fix the half tank lean by dropping the mount level of the tank below the level of the carb? Not that this is an option, just wondering..

 

[4x4]

i thought i had half tank lean but if you just press down the fuel tank cap until it clicks it was fine just worth a try before you start doing the header tank.

 

[Fx]

i thought i had half tank lean but if you just press down the fuel tank cap until it clicks it was fine just worth a try before you start doing the header tank.

Already did that I also tried using my aluminum tank where you screw on the cap, and no luck still the same results.

 

[snoop69]

Nitro engines will run without the pressure line attached
to the exhaust (some don't have a nipple on the pipe) so
the header tank ensuring constant pressure must be a
myth also:Mr.confused:

 

[polystyrene]

okay heres what 'half tank lean' really is.

"the carb pick up is below the top line of the tank (when fitted to a Savage) as liquid finds its own level its much richer at the start than at the end, because at the end of the tank the fuel level is below the carb pick up.

On a buggy/truggy the entry to the carb is higher than a full tank of fuel."

personally i never expereinced it, but a mid tank mod will not fully cure this supposed problem, as the carb is still higher up.