As u all know and have experienced, the engine runs leaner when half a tank is gone. so why is that so? i just can't find a solution. i'm using 25% tornado fuel or 25% o'donnell. i've put a cold plug onto my engine, put on longer fuel lines but nothing seems to work. the cold plug made it a lil better but it still gets 2 lean at half a tank. This problem has been acheing my head for the whole year i've had the savage. every time i drive or go to the track i have to screw with those high- and low speed needles. it sucks. Please help!!!

The problem is with the shelf on the top of the tank. Do a search on 1/2 tank lean for more info. Fixes include adding another small tank or switching tanks all together.

ok..i read it. so the solution is to get a New era tank? tht is not like the hpi savage tank (at half a tank it's much thinner)

You can also look into the "header tank mod" and the "mid tank mod".

i found the tank [link=http://www.neweramodels.com/item.cgi?session_id=aydppyhdwvthovidwaaixrxltgoqwu sj&part_id=1704]Click here 2 see it![/link]
so this will solve the problem? does this tank fit with [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=001242108&I=LXPZM8&P=K]THIS TANK GUARD[/link] ???

You can get the tank here for 10 bucks

http://www2.towerhobbies.com/cgi-bin...?&I=LXBM24&P=7


Then just spend a 1/2 hour making minor modifications so it fits the stock posts.



See this tutorial created by DaToOLmAn


Ok finally got my pics working ops: here it is and btw I've ran about 8 tanks with this tank now and I much prefer it over the original it really worked out well.......


Well after much frustration with the savage 's 160cc L-shaped fuel tank, I decided to try the Ofna 125cc tank. I have the 25 rtr with the new tank design and it still causes 2 main problems....it still leans at half tank , but more than that is the way its mounting is designed . I cracked the tank on a hard landing because it sits right on the top of the frame rail , and the impact from jumps eventually causes the the frame rail to shatter the bottom middle portoin of the tank .Anyhow , i ordered the new tank and when it came in I was looking at possible ways to inexpensively mount it. Turns out you can get the tank to mount securely with the factory brackets and i little modification .This seems to work out great for those of us who are fed up with the tank problems and are on sort of a tight budget ,with the only drawback being slightly shorter run times. The tank design is rectangular with no "shelf" to change the fuel pressure at a half tank. Best part about this mod is the hole sha-bang only costs about $13 Heres the mod....

First off , you'll need a few simple tools to do it right .

-#2 screwdirver
-drill
-3/32 and 3/16 drill bits
-razorknife and/or course file
-measuring tape or a ruler.

Now for the (3) parts you'll need.

1-The Ofna fuel tank. http://www2.towerhobbies.com/cgi-bin...?&I=LXBM24&P=7 OR http://store.savagess.com/advanced_s...ecbbdd340bf403
2-extra fuel line , if you have an extra 10" of fuel line , you can just use that if not .... http://www2.towerhobbies.com/cgi-bin...?&I=LXFEP9&P=7
3-1 15mm screw Hpi part #z569 (see pic below) this is the screw from the steering arm on the servo saver on the Savage .if you have a spare screw that is identical to this one it will work fine , if not it only costs 95cents. http://www2.towerhobbies.com/cgi-bin...?&I=LXM671&P=Z
Heres the parts..



Now to get started...First remove the REAR tank mount bracket by removing the phillips head screw that holds it in .
Now looking at the pic below as a guide cut off the top round section of the bracket with a razorknife or similar tool (plz be very carefull :wink: ), and file any extra material off the bracket to make the top nice and flat.


Now you'll want to drill a hole in the top of the bracket with the 3/32 drill bit going only 1/2 inch deep at most , making sure you are as close to center of the top of the bracket as possible .

mine was slightly off center :roll:


Now you are ready to re-mount the bracket to your truck. The bracket gets installed in the oposite way it was originally . You may have to detatch the header pipe from the engine to be able to fasten the phillips screw from the other side of the truck .



The bracket is a tight fit but it doesnt disturb the movement of the shock shown in this view from the side .


Now to modify the Ofna fuel tank ....install the 2 brass fuel fittings into the tank ( they come with the tank) Now look at the front mount , it is too thick to fit over the mount on the front bracket of the truck so you will need to cut it down with your razor knife or file . File or cut the mount from the BOTTOM side of the mount( do this in small shavings and be careful not to cut through the outside of the tank or your fingers! :wink: ) The result should be a 1/4 inch thickness of the front mount of the tank .
this is the front of the tank.


here is a side view showing the 1/4 inch thickness of the mount after shaving it down.


Now drill the existing front mount hole out to 3/16 , you might have to "wallow" the hole out a bit larger for it to fit but use this size bit because you want it to fit tight .Drill the tank from the BOTTOM.


Now you are done with the front mount , on to the rear mount . You will need to file down (or cut) the rear mount from the side until it is flush with the installed fuel pickup fitting , when looking at it from the top .(see pic)


Now with that done one last step with the tank...drill a hole in the rear tank mount with your 3/32 drill bit , again drilling from the bottom of the tank . The hole needs to be placed to the RIGHT of the original mount hole when looking from the BOTTOM of the tank .Be sure your looking at it from the bottom as seen in the pic below before you drill Be very carefull here to drill in the centered section of the mount between the original mount hole and the right side of the mount , if you go to far to one side or the other you could split the mount or crack it and thats bad :evil: . Drill slowly and get the bit centered perfect before you drill . The pic shows where the hole should be when you are finished .Sry its a bit blurry but thats the new hole (smaller of the two) on the right of the mount .


Almost finished now , take the tank and install it into its new brackets on the truck , it will be a tight fit . Once the front mount is in place slide in the original body clip that holds it down .***


Now with your 15mm screw , attach the rear mount (the screw will thread into the tank mount so make sure to hold the tank down firmly when screwing it in , so you dont have a gap between the tank and bracket)


Make sure the tank fits well and you should have clearence between the tank and the chassis plate , you can see a small gap between them in this pic from the top .


Now just install the fuel lines and your ready to bash , and hopefully no more fuel tank issues . ***If the tank doesnt sit even on your truck file the rear mount on the truck down more to get it even with the front one so your fuel wont gather at the front of the tank when almost empty.

Cool, i hadn't seen that before.

Here is one that not too many people know about. This is the one I want to do but I am not sue if it requires extended FLMs or not.

These are some pics of zoomer s' truck and the 150/160cc tank mod.









[img]http://i184.photobucket.com/albums/x312/zoomer_02/P5090003.jpg
[/img]

ok but does it fit the tank guard?

On ZOOMERS truck, what tank is that and what all is required to do that mod? That's more of what I am wanting, I really don't want to go from a 160cc tank down to a 125cc. I know it's only a few mins off the run time but I truely don't want that, I run right about the same as my buddies trucks as is and I don't want to cut it down more.

Has any one tried a Perry pump to see if this cures the half tank lean problem? I am like some and do not want to go to a smaller tank. I only get about 10 to 12 minutes at the most on my buggy running 125cc with a 21 engine so I know the bigger engines will give me even less run time.

i run about 20min with my f4.1 engine with a 160cc tank. just calculated and i should run 15min with the same engine

but any other solutions? not the pump... lol
witch is better....the mid tank mod or the header tank mod....and witch is easier? :P
instructions would be nice also
Thank u!

I know if it where not for racing my buggy I would try the Perry pump. Right now the race budget does not allow any extras. I still do not even have the STS 3 port 28 I have had for six months totally broke in. [X(]

Never owned a 4.1 but it is not known to be the most high performance engine. I do know my K4.6 when I raced it got around 15 minutes on the track with stock tank. Now if you get the LRP or any other high performance engine see what your run time is after cutting out 35cc!

but how do these mid tank mod and header tank mod work? if theyre easy then i'll try to make it instead of a new fuel tank.

A lot has to do with what you are going to do. I will all ways try keep my truck sanction legal so if I do race it and with a header tank it would not be so. Now I am not sure a Perry pump would be either. I know the mid tanks are and going to the 125cc tanks is but going to a smaller tank when racing means more pit stops. When going to a mid tank you put the tank where the radio box goes so you have to relocate and make brackets for servos and radio equipment.

It is a Mugen 150cc tank

Cool wonder how it would work on stock length TVP chassis? Do you have a rough measurement from mounting hole to mounting hole?

I do not have the tank or any measurements but this thread contains 2 people that have installed it on EXT and regular length TVPs.

[link=http://www.savage-central.com/modules.php?name=Forums&file=viewtopic&p=620865#62 0865]http://www.savage-central.com/modules.php?name=Forums&file=viewtopic&p=620865#62 0865[/link]

I just checked and it will not fit on a stock length chassis. Thanks

Does anybody have a link to that tank?

I think this is it.. [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXRYV8&P=7]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXRYV8&P=7[/link]

Did you check out that other thread? evo165 has some pics with it on regular length HPI carbon fiber TVPs.

No I did not look till you just said something. Yes the shocks and the brake throttle linkage is the problem but looks like he has where it is working on his. Wish the pictures where a little bigger! I still have some concerns as it is very low and close to the shocks.
Thanks for pointing this out.