air bubbles

[funwheels1]

hey,
Man, idk where they are coming from but there everywhere. BRAND NEW hpi savage tank, BRAND NEW fuel line. Man, theres airbubbles everywhere. It runs about an eithgh of a tank, i check to see why it stalled and theres like 2 inch air bubbles in my lines? Any suggestions. Man, this thing made me so mad i snapped the pullstart string =(.

Drew

 

[billkalicious]

If the tank has a primer, that's probably the culprit. I have that problem currently. I installed a header tank to trap the air in the fuel line so the carb gets a steady stream of fuel. More weight, but hey, it's more fuel to run through too!

 

[funwheels1]

hows that working for you? I mean my air bubbles are BAD

 

[TRDStreetFighter]

I am using the new Savage tank with no primer ... no bubbles at all for me

 

[SkyMaxx]

Your problem could be an airleak or it could just be the bumpy ride. Try a spritz of Armor All in the gallon of fuel(not in your fuel tank, but in the bottle of your fuel). This takes away the tendancy that fuel has to foam or get bubbly when shaken. Only a spritz...no more.

If after doing this, you still have a ton of bubbles...time to seek the air leak and put an end to it. I'd start with the primer on the fuel tank and work my way around from there.

 

[billkalicious]

Sky's right on finding the source. That's important. My leak is a result of the primer. My bubbles were quite bad as well. I didn't want to mess with removing the primer. After reading some posts on the procedure, I was too worried I'd mess something up (possibly an engine if parts of the primer ended up there). Basically, the header tank will fix problems that are related to air coming from the tank. Doesn't matter how extreme they are, the header tank will absorb the air. If the bubbles are really extreme, you might have to stop and refill the header tank occasionally since it will fill with the air from fuel line going to the main tank. I usually check it on a fill-up. My tank only holds about a cup and only cost about three bucks.

You might check the cost of a replacement tank (sans primer). The cost of the new tank might out weigh the time of installing the extra tank. I can take some pics of my install if it would help.

 

[funwheels1]

please post pics of been thinking about doing that tank mod just dont know how.

 

[billkalicious]

Don't have too much time, going out of town for the weekend. I took these pics real quick and put them on my server. Haven't posted pics to this site and can't take the time to learn tonight.

Basically, the fuel flow is like so:

Original Tank -> Short pipe that empties at the top of the header tank.
From the header tank (with a filter klunk) to the carb.
From the muffler to the cap of the original tank.

The fuel goes from the stock tank to the top of the header (fuel naturally falls to the bottom) and from there to the carb.

One note on priming the engine. I haven't spent enough time trying to figure it out so I just pull the line off of the muffler and blow air into it until the fuel reaches the carb and one more small breath. Not an exact science for sure.

Here are the pics, they're large so you can see detail. Hope they help.
http://www.kcghost.net/10100001.jpg
http://www.kcghost.net/10100002.jpg
http://www.kcghost.net/10100003.jpg

Good Luck!

 

[SkyMaxx]

This would be variation two on the two tank mod.

Here's another member's solution (pics included):

https://www.rcnitrotalk.com/forum/showthread.php?s=&threadid=6658&highlight=two+tank+mod

Let us know what you do and how it works out for you.

 

[wdavidhicks]

Armor All in the fuel, Sky? I never heard that one before.

 

[SkyMaxx]

Ask Christian for more details. It is his tip from a while ago. Do a search for Armor All and I'm sure you'll find plenty of info on it here.

 

[billkalicious]

Wow. My first run with the Savage out of my yard. Went to a concrete/dirt/rocks/whatever dump ground. What a blast. Looks like I'll end up replacing my stock tank with the new primerless one after all. A rough set of rolls and flips and my tank has a nice hole in the back. I should have paid more attention to that post about the shocks and fuel tank problem. Oh well, enough duct tape will fix anything, at least until my new tank comes in.