Air bubbles building up in fuel feed line.

[svecobrar]

Hey guys I need help. I have classic tmaxx with a 2.5, and the truck runs pretty good but it runs a bit too hot and i've tried sealing the engine and all thr basic stuff. One thing I have noticed is that the fuel feed line is constantly full of air bubbles.

Ive put a brand new gas tank in it and ive tried a few different fuel line routings to try and keep the fuel as cool as possible but I feel that the heat is still getting to the fuel and causing vapor lock.

I have three other nitro monster trucks so im not a beginner by any means but am not a expert either.

Thanks in advance

[REVO-5309]

there isnt enough back pressure going through the exhaust to push the fuel through the line.... check the header seal

[2revo1maxx]

Is it a brand new tank? Are all the screws in it and tight? A loose or missing screw can cause foaming.

[Phins Fan]

Do you have anything else in the fueline like a filter or a finned cooler? Those extra breaks in the line can cause airleaks as well.

[svecobrar]

I don't have anything else in the fuel tank or on the line. I guess my next step would be to check the header seal. Can i test it for leaks with soap and water while it runs?

Also does the stock pipe on the tmaxx make it sound like the idle is high compared to, lets say a revos? My stock piston and sleeve are out getting repinched so i put my revo 2.5r in it for the time being, same fuel line systems by the way, and it seems like the 2.5r idles a lot higher in the tmaxx then in the revo.

Thanks again.

[REVO-5309]

just blow into the exhaust pipe. if pressure doesnt build up then there is a leak somewhere. if u blow into it and when u stop the air rushes back out then its tight...

[2revo1maxx]

So the screws are all in and tight then?

[svecobrar]

Ya the screws are in and tight. Its alot easier putting the tmaxx header on compared to.the revo one so I know its on there good. Ill be checking the exhaust for leaks in the morning.

[2revo1maxx]

I meant the fuel tank, make sure it's secure.

[svecobrar]

Ya the fuel tanks secure, i've removed it a bunch of times and its solid. I'm going to try the suggestions about the header gasket tonight or tomorrow, whenever i get my parts in from rcrenew and amain so i can do everything at once.

[svecobrar]

I replaced the exhaust to fuel tank fuel line and it helped with the air bubbles but they were definitely still happening and causing some problems although the idle went down very noticeably. I didn't have time to swap out the tank as it was because i was racing my buddy's lrp .30 savage x and didn't want any down time.

I did check the exhaust for leaks and none were found. And i did notice that when i fill the tank full i get fuel that goes into the pipe to tank line. Is that normal?

[Pope]

Replace all fuel lines and check all seals on header and fuel tank. You may have a clogged in tank filter and need to replace the tank.

[2revo1maxx]

Just get a new tank, it obvious that your problem is with that.

[svecobrar]

thanks i'm going to swap it after i swap the springs on the mgt 8.0 i just bought.

[svecobrar]

swapped tanks but still having the same problems. The car runs pretty good with the newly repinched motor but it tends to run hot so i bought a golden horizons cooling head and we'll see how that goes.