Good morning all, I have a Stihl chainsaw model 025 that I just replaced the vent line on the gas tank when I start the chainsaw and try to rev it up to cut wood I start getting fuel pressuring up the vent line and leaking out and the chainsaw is acting like the choke is on. Just seeing if anyone has experienced the same thing and might have a suggestion for a fix on this problem.
Stihl 025 vent line fuel leak
- Thread starter Lite69318
- Start date
Help Support Arborist Forum:
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
Put up a pic of your vent
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
Where does it leak at?
Try flipping it over.
Try flipping it over.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
What does the fuel line look like?
The vent line is symmetrical it's the same on both ends flipping it over won't do any good. The fuel feed line from the tank is a black rubberized line that comes up to the side of the carburetor. The fuel line from the tank looks intact.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
Any cracks in it?
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
The insert on the top looks like it is farther in the fuel line, and might allow the fuel line to go down farther on the nipple.
Which is why I asked where the fuel was leaking from.
I am guessing that you have a severely cracked fuel line. Try bending the line with your fingers and looking.
Take a pic.
Which is why I asked where the fuel was leaking from.
I am guessing that you have a severely cracked fuel line. Try bending the line with your fingers and looking.
Take a pic.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
And if your fuel line is cracked, you should rebuild the carb, as dirt/gunk is in your carb as well.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
But I am just making an "educated" guess, assuming a lot, and why I always ask questions, and request pics.
Most guys here just blurt out "Replace the crankcase seals"!!!!
But I am guessing that you had a leak, had a crumbling vent, and the saw ran like ****. You replaced the vent, it still leaks, and still runs like ****.....
Most guys here just blurt out "Replace the crankcase seals"!!!!
But I am guessing that you had a leak, had a crumbling vent, and the saw ran like ****. You replaced the vent, it still leaks, and still runs like ****.....
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
Being an 025, it means that the saw is real old, and the fuel lines on that series of saw was/is notorious from cracks between the tank and carb, but to see the cracks you need to bend the line, and the cracks really open up. Also, the part that dangles in the fuel can get real soft, weak, and gummy, and be a big problem there as well.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
OK, not trying to be mean, but the fuel lines are a big weak spot on this model.
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
What work have you done? Your first pics show it with the carb off already. Did you replace something recently? What led up to the saw not running correctly? Not just the replacement of the vent?
If you have a pressure/vacuum pump, you can check the fuel line by pulling the line out of the tank with a hook, plugging that end, and putting pressure (and vacuum) on the other end and see if it holds. Bend it around while the gauge is on it to bring out any small cracks. Also try twisting it where it goes into the tank - should be snug and not able to be moved easily.
dougand3
Addicted to ArboristSite
If fuel line is fine, I'd try an Echo tank vent.
walterg
ArboristSite Operative
It doesn't look symmetrical in the pic.
Do you mind taking it off and posting a pic.
Either way the top grubb screw should be almost even with the top of the hose. Bottom grub screw doesn't look high enough.
Not sure if that would make
a difference or not.
The OEM Stihl vent is about the same price as that aftermarket one you bought.
Sent from my LGLS775 using Tapatalk
- Joined
- Dec 6, 2014
- Messages
- 21,161
- Reaction score
- 24,999
Yeah, I was just wondering if the vent line needed pushed on the nipple further. Either way, he could just push them in a bit more with a small screwdriver, as their placement is not critical. I am curious where this fuel is leaking from, as that would probably tell us something.
His running problem isn't the vent though, well that could be easily tested. Just take it off, and start it.
His running problem isn't the vent though, well that could be easily tested. Just take it off, and start it.
Ok, so originally the saw started acting up wanting to stall while cutting. When I took the back cover off i noticed the missing vent line. I ordered the new line put it on and it didn't fix the problem. So yesterday I took the carb off to see if it might be dirty inside. Took out the diaphram and needle also took off the bottom cover sprayed it out with carb cleaner and put it back together, re-installed and tested it, same symptoms are present. Idles just fine but when i try to throttle up it acts like it has been put in full choke position. The fuel was bubbling up inside the new vent line and coming out the top. Up till now this saw has never had to be worked on and it is anout 20 years old, so I have been fortunate up to now.
