Echo CS 346 Air shooting out of my gas cap?

It was running good for a while, then when I shut it off it was hard to start, would run for 20-30 seconds and die, I get it going and it would run OK until I turned it off, I checked the gas and when I opened the cap a rush of air came out, did that 2 times , I think that means something what is it?
I didn't try to do anything with it I was busy, got tired of pulling on it, so I just went and got a different saw

 

Hmmm - rush of air coming out, verses sucking in? Sounds like classic vacuum issue from bad tank vent, but should create a vacuum in the tank (no air being allowed in from the tank vent), so cracking the cap should cause air to suck into the tank, not rush out. Are you sure it wasn't just a 'sound of air' rushing past the cap when you cracked it open vs. air definitely rushing out of the tank? I can't think of a reason why you would have positive pressure building up in the gas tank and cause air to rush out. So, I think you have a bad tank vent. After you crack the gas cap, will it run fine, then die again? Try this a couple of times. If the saws will keep starting after cracking the cap, then die - most like problem is bad tank vent. Cheers!

 

Hmmm.....missed this part. If tank vent, wouldn't guess that sometimes your can run it until you decide to shut off (running for a while?). Otherwise, tank vent makes sense. How long has the saw run when you decide to shut off vs. die? Cheers!

 

I can't say for positive that the air was coming out but the last time I did it there was a lot of air moving there, the tank was full and I had started it about 3-4 times, and when I loosened the cap it splashed gas out on my arm and in my face. I don't know but it was acting like opening up a pop that was shakin up some, but that was just that one time the other times I just thought that the air was being sucked in.
I thought something was up buy that air sound when I opened the cap, so I was opening it to see if it would run after I had opened it but it didn't help.
So there isn't supposed to be any air sucking or blowing when you open the cap, if the saw working right, is that right?

 

I was only running it about 15-20 minutes at a time

 

Could it have got hot. heated the fuel tank & caused it to pressure up ?

 

I don't know but from the time I started using it to time I put it away it would just kept getting worse.
But when I was running it it sounded good to me and was running good, when it was running it would set and idol good to, but after a while it wouldn't idle either it would die out

 

Check your exhaust. does it have a screen ? could it plug ?
Maybe blow back from the exhaust somehow .

Weird problem.

 

I was just thinking about that screen seems to me I cleaned it out or checked it last summer .
I'll probably I have to get out there and check out the simple things first and run it a bit see more what maybe the problem.
When it was acting up I get it running and then give it gas and then it would die right out.
I had it tuned good last summer and it ran great I haven't messed with tuning for anything at all so far this year, just started it and started using it

 

This sounds like possible crack in fuel line. But....wouldn't explain the first issue related to air from the cap, unless it is just normal pressure and you are listening for it this time since the saw is acting up. Cheers!

 

no I wasn't listening for it and was not expecting it, it was obvious I had never heard a saw do that before.
How about pumping the chit out of the primer bulb will that a add more pressure
I looked at the IPL for the tank vent so I kind of know what I am looking for just don't know exactly where it is.
So it is just a line that comes out of the tank somewhere and ends with a valve doohickey on the end right?

It looked like the primer bulb was only getting like a quarter full, when I first started it up and pumped the bulb it got filled right up

 

Is this the fairly new one you bought last year or year before ?

Time to go thru it
Air Filter,
Good new fuel & check fuel filter
Pull Spark plug ( look inside) maybe a new plug
pull Exhaust & look inside, clean screen if it has one.
Not sure how to check the fuel lines. may have to take it way apart to get at them.

You & I both have old Husqy 61s that run fine after 20 - 30 years.
This saw ain't close to that old.

 

bought it off of craigslist couple years ago for 60 bucks
I do believe I did check the muffler screen, don't think I even put a new plug in it, cleaned the air filter, turned it , put fresh gas in it, been running good up till now.
I'll just have to start taking it apart and have a look see.
Get some help from my friends on here, a few little new parts, and I'll get it going again, I love my little 8 pound Echo

 

Tank vents can vary, but I looked at the IPL for your saw and looks just like you describe. Simple rubber line entering the fuel tank with the tank vent on top. Not sure location on your saw - haven't ran one - but probably somewhere near primer bulb? Probably covered though - perhaps under air filter cover and to side of carburetor? Should be able to look inside gas tank and see the main fuel line and primer line, as well as one other line entering the tank - that's the vent line - then follow up from there. I don't think pushing the primer bulb many times would have any effect on the pressure in the tank.

How is the saw idling when you first start it? When you blip the throttle, does it bog? Cheers!

 

just before I put it away, when I got it to start as soon as I bliped the throttle it would die

 

Any time to work on the saw today.
Inquiring minds want to know

 

Nope ,I'll let yawl know

 

Right when you start the saw cold next time, see if you get the bog (or the saws dies) when you blip the throttle. If so, you may need to tune the carb - specifically the L needle - and see this this helps solve the problem. Bogging at cold start shouldn't be related to tank vent, but could still be cracked fuel line. Cheers!

 

Running pretty good now ,I don't know what the deal was with the air when I opened the cap.
I will explain more when I load the pics