Help: Air in Carb lines

[Mule03]

Engine cutting out and I noticed air in the carb line to and from the carb to the fuel tank. Priming the bowl I see more small air bubbles. I have replaced both fuel lines but that didn't resolve the problem, any thoughts on what else to check?

 

[rcnut14]

what if u just bleed the gas lines until all the air goes out?

 

[Mule03]

I will give that a try and see what happens, btw I believe HPI support must be hearing customers are not happy at all with this product. I called them again today to see if they had any suggestions on the air and they didn't but they are sending me a new fuel tank and carb.

 

[F-Type]

I noticed some air bubbles in the return line and in the prime bowl, but didn't think much of it as it's on the return side, but perhaps it is a sign?
I will check the to-line as well, now.

But if the to-line shows no bubbles, is this still something I should check out, I wouldn't have thought so?

 

[rcnut14]

I will give that a try and see what happens, btw I believe HPI support must be hearing customers are not happy at all with this product. I called them again today to see if they had any suggestions on the air and they didn't but they are sending me a new fuel tank and carb.

yes, it is a new product, and there are some issues with it.

I noticed some air bubbles in the return line and in the prime bowl, but didn't think much of it as it's on the return side, but perhaps it is a sign?
I will check the to-line as well, now.

But if the to-line shows no bubbles, is this still something I should check out, I wouldn't have thought so?

bubbles in the bowl isn't abnormal, I honestly don't know if theres supposed to be any in the return or not. if it runs good, just keep runnin it I guess.

 

[F-Type]

Just noticed that the to-line is all black, no way to see any bubbles in that one.

However, there usually is air in the prime bubble on other 2 stroke engines as well, like the brushcutter.

Still it would be interesting to know where, and why, air gets into the return system like that. One assumption would be that the prime bubble is pumping more than the to-line can supply in a reasonable way, and therefore there's an "air release valve" somewhere in the system to prevent to high negative pressure.

 

[rcnut14]

it's possible. u would have to remove the carb and take a look at it. Ive never looked at one, but I cant imagine it's that much different then a carb on a small chainsaw or weedeater.

 

[F-Type]

When I tried pushing and releasing gently on the bubble primer, no air bubbles comes through the return line. Strengthens my belief in my assumption above

 

[F-Type]

I've done some further "investigation" into this matter recently, and I am close to 100% sure that the air is entering between the primer bulb and the primer base, hence, it has no impact on the carb functionality at all.

 

[J.LO's SAVAGE X]

ok, common problem, start checking lines, replace them just for cheap measure gasket seal under tank lid.

 

[F-Type]

In my case I'm pretty sure it sucks air in at the primer bulb, and I haven't seen any fuel leakage "the other way", so no reason to do anything, IMO. I have noticed a similar behaviour on my 2-stroke garden tool and they all run fine.