Gas tank vent question

[junkman]

If a gas tank vent is malfunctioning ,would the saw start crapping out when gets down to 1/3 of a tank of fuel ? I noticed the vent dripping when tank was full also saw on its side ,cap down .

 

[Chainsaw Jim]

Malfunctioning vents don't typically wait until near empty to act up. Which model?

 

[Gunn]

Is the tank holding vac?

 

[MustangMike]

May be a leaky cap? When I had a vent problem on an 044, it let me know much sooner than that.

Wish I knew a way to check if that is the problem.

 

[stihl saws]

Which saw would be my first question?

 

[MustangMike]

He runs mostly hybrids, so I'm assuming it is a 044 or 440 tank.

 

[Canadian farm boy]

If a gas tank vent is malfunctioning ,would the saw start crapping out when gets down to 1/3 of a tank of fuel ? I noticed the vent dripping when tank was full also saw on its side ,cap down .

This wouldnt happen to be the same saw that you had to put a carb kit in earlier this year?

 

[stihl saws]

I had a Stihl (02 something) years ago that would not run below about 1/4 tank . Finally figured out the fuel filter became exposed and couldn't pull gas. May have had the wrong fuel line. Didn't keep it long enough to mess with it.

 

[junkman]

Malfunctioning vents don't typically wait until near empty to act up. Which model?

Stihl ms440 , it rides like this ,cap and vent down ,has never leaked ,was dripping on the ground saturday ,before that the saw was cutting out when fuel level went down ,i refilled and it ran fine at that point ,i did pop off the vent cap with my pocket knife ,and blew with compressed air around the vent ,it started peeing fuel at that point for a bit ,have not put any real time on it since so not sure if fixed it or not yet .

 

[junkman]

This wouldnt happen to be the same saw that you had to put a carb kit in earlier this year?

I never kitted it ,just took it apart and blew carb cleaner through it ,the needles were gummed up ,saw hauls the mail so it is not the carb ,either the vent or the green fuel line i guess ,the leaking vent led me towards the vent as the problem .

 

[MustangMike]

At least on the 440 (as opposed to the 044) replacement vents are easy to get. I would just try replacing it and see if it solves the problem.

When my 044 vent leaked, the saw ran fine. When I tried to fix it and the tube I used was softer and did not breath, the saw died right away. I eventually got it to work with parts from my broken tank handle (used some stuff from each saw), but could not find replacements for it anywhere.

 

[junkman]

At least on the 440 (as opposed to the 044) replacement vents are easy to get. I would just try replacing it and see if it solves the problem.

When my 044 vent leaked, the saw ran fine. When I tried to fix it and the tube I used was softer and did not breath, the saw died right away. I eventually got it to work with parts from my broken tank handle (used some stuff from each saw), but could not find replacements for it anywhere.

Those 044 vemts are horrible ,always drip fuel

 

[Chainsaw Jim]

I'd use a brand new oem vent.

 

[super3]

Are you using the large filter?
That wouldn't have a thing to do with it leaking but, the newer fuel lines seem to be stiffer.
I have had to replace several that use the smaller filter with the large one to get it to pull the line into the bottom of the tank.