Air in fuel line

[bplakers]

I have some bubbles in the fuel line. I've already checked gas tank fuel lines filter for leaks. Checked on the motor also didnt see it leaking from anywhere. But when I go to prime it its fine then as soon as I take my finger off the exhaust it immedietly starts backing up in the fuel line making bubbles and that. Engine was just running great the other day took it out today had this problem with it. Right now the only thing I can think to do is try a new exhaust if that would help idk if it would or not. Thank everyone ahead of time for the help on this.

Its on a hpi k4.6. Also I was wondering about the fuel tank I have it has a hose going out the bottom as a vent I guess none of my other vehicles have it just this one.

 

[Phins Fan]

Have you leak tested yet? May be a pain but disconnect your entire fuel system and plugging your pressure line going to the carb. Blow in the other end while your tanks submerged under water. If no leaks try reversing it. If no leaks than your tank should be fine and you can concentrate on fuel line and filter.

 

[REVO-5309]

checked the exhaust? from block to the pressure hose? could be letting pressure out before the pipe. eg header?

---------- Post added at 9:55 AM ---------- Previous post was at 9:54 AM ----------

blocking the end just gives it enough pressure to push the fuel.... could be totally wrong tho lol

 

[bplakers]

Ya thats what I'm thinking can't find a leak on it anywhere. Exhaust garmet is a little worn. Sucks I dont have one of them.

Tried my xl fuel tanks and lines same thing happend took fuel filter off just incase tried it withe xl tanks same thing.

I think I have a new header to pipe garmet I might try that if it'd help.

But ya it will suck up the fuel with finger on there the pipe while turning over as soon as u take ur finger off to put glowstick on there can see the fuel just run back into the tank. When I had the motor in the truck it would start and that but had no power at all. Will start now but its about a 2 person job. Even when got it to rev up on stand still doesn't seem like has much power.

When I had it out earlier this week was doing wheelies on command idk what happend put after run oil in it let it sit for a few days went to take it out today had that happen

 

[bplakers]

Well I didn't do much to it just took it apart added a washer and made a gasket it was missing just took it out running like a champ again no fuel bleeding back through the line. I did change the garmet from the header to muffler was the only 1 I had so.

Thanks for all the tips