Pull fuel supply line off carb (Huskvarna) and it continues to spray gas (against gravity!)

[777funk]

I'm guessing the tank is getting pressurized BUT... I don't know how as the saw wasn't run (cold engine) so temp should be ambient. And... All I did was turn the saw on it's side then back up. It's like old faithful coming from the tank below out of the fuel line. I can't stop it until I open the gas fill cap and screw it back shut. But, tip the saw to get the flow going again and it just keeps going.

Is this normal?

 

[Fatherwheels]

I can't see it as a problem. As long as the tank doesn't empty into the saw,
which is unlikely due to the metering valve spring keeping the valve shut
until the engine vacuum kicks in. The tank valve may only be allowing the
pressure to escape one way, some valves are two way and don't allow pressure
to build in the tank.

 

[Huskvarna hotellgäst]

Sounds like the tank vent is blocked.

 

[777funk]

Sounds like the tank vent is blocked.

My saw looks pretty similar to your avatar. It's a 281xp I believe (going off memory) with a metal chain brake loop. Where is the tank vent on these old saws?

 

[777funk]

what model number and how old is the saw.

281XP and I don't have a date on it but metal loop for chain brake and I'd guess mid 80s.

 

[president]

Sounds like the tank vent is blocked.

tank vent only allows air in to replace fuel sent to the carb.
(nature hates a vaccume ) is the old axiom

 

[TBS]

Vapor pressure will push fuel out and sometimes if your fuel line is the right length and enough fuel is in the line it will siphon out. Gets annoying when you don't realize the fuel line came off and gas is flowing everywhere even though the saw is sitting level.

 

[old CB]

Was this saw sitting in the sun when this happened? Especially if you are located at higher elevation (in the mountains) a saw sitting in the sun gets super warm, and every liquid boils at a lower temp up here. During the workday we have to hide our saws from the sun to keep from having the fuel boil in the fuel tank.

 

[777funk]

Was this saw sitting in the sun when this happened? Especially if you are located at higher elevation (in the mountains) a saw sitting in the sun gets super warm, and every liquid boils at a lower temp up here. During the workday we have to hide our saws from the sun to keep from having the fuel boil in the fuel tank.

Unfortunately it was indoors (in my living room) when this happened. I was cleaning the carb on the kitchen table and noticed it leaking gas on the (unfinished) floor. Thankfully I caught it before my wife mentioned there was a problem... lol.

 

[67L36Driver]

Always have a golf ‘T’ handy when disconnecting the fuel line.

Cracking the fuel tank lid helps except for full tank.

 

[Old2stroke]

All is normal. With experience, you learn to drain the fuel tank, or a least loosen the cap if it's on top of the saw before you pull the fuel line off a carb. Once the line is off, you can plug the end of the line and tighten the cap. Getting sprayed in the face a few times helps one remember to do this.

 

[pioneerguy600]

Hemostats are your friend when working on rubber lines or a suitable plug like a golf Tee as already mentioned. A slight change in temperature or any agitation of the saw, ie, turn over or a shake will send the fuel out the line no matter the orientation of the line, just the way fuel/gasoline reacts.

 

[old guy]

Happens all the time, like 67l36driver said a golf tee works well.

 

[Huskvarna hotellgäst]

My saw looks pretty similar to your avatar. It's a 281xp I believe (going off memory) with a metal chain brake loop. Where is the tank vent on these old saws?

The tank vent assembly is in the center of this image, part number 501 62 96-01.
At it's core is a "pill" of sintered polymer which should allow air/fuel vapor to pass in either direction but not liquid fuel.
However, due to the (frequent) possibility of fuel leakage through the "pill" it's housed in the horizontal tube with an opening at each end.

 

[Huskvarna hotellgäst]

tank vent only allows air in to replace fuel sent to the carb.
(nature hates a vaccume ) is the old axiom

Only when the saw is on its side or the tank is completely full.

 

[Okie]

What is the model of your saw and
does it not run correctly.
Reason I ask about model of saw is not all gas tank venting is the same.
Some only let air in and will hold a pressure and the carb needle and seat holds back to pressure.
So your description may be normal thing.

 

[Dennisthemenace]

Pretty normal, especially older saws, just empty the tank before maintenance

 

[777funk]

I believe this pressure build up is causing running issues. I can run it out of a can of gas and it runs fine. But not so with the tank (pressure build up).

I've got to figure out a way to relieve the pressure. I pulled the vent assembly and don't think I saw anything unusual. MAybe have to pull it again. It won't run with this pressure build up.

 

[Okie]

If it's like post 14 you have a clogged up vent.

What is the Model of your saw????????????
I test vents with a pressure/vac tester, mityvac type.
You can sometimes make a vent using a piece of tubing and a GRUB screw like Stihl used on their older saws. If you use a grub screw do not TWIST it into the tubing, push it in so as it vents around the threads. I've tested them with a mity/vac and sure enough if you twist/screw them into place they won't usually vent around their threads because the threads cut into the tubing especially if the tubing is soft.

Some gas tank vents do not relieve pressure to the atmosphere, they only let air in to prevent a vacuum so as to prevent global warming and to give Al Gore more money.

 

[Woodslasher]

If it's like post 14 you have a clogged up vent.

What is the Model of your saw????????????
I test vents with a pressure/vac tester, mityvac type.
You can sometimes make a vent using a piece of tubing and a GRUB screw like Stihl used on their older saws. If you use a grub screw do not TWIST it into the tubing, push it in so as it vents around the threads. I've tested them with a mity/vac and sure enough if you twist/screw them into place they won't usually vent around their threads because the threads cut into the tubing especially if the tubing is soft.

Some gas tank vents do not relieve pressure to the atmosphere, they only let air in to prevent a vacuum so as to prevent global warming and to give Al Gore more money.

Earlier he said it was a 281 Husky, fyi.