stihl 290 acts like it is out of gas when the tip is pointed down

[grand lake]

I have a stihl 290 the runs fine as long as the saw is level or the tip is pointed up but when the bar is pointed down the saw dies like it is starved for gas. It will start again and run fine until the tip is lowered again. It will run for a short time pointed down if I am on the throttle. Has anyone else had this trouble and what fixed it?

 

[Stihlofadeal64]

I have a stihl 290 the runs fine as long as the saw is level or the tip is pointed up but when the bar is pointed down the saw dies like it is starved for gas. It will start again and run fine until the tip is lowered again. It will run for a short time pointed down if I am on the throttle. Has anyone else had this trouble and what fixed it?

It could be a tank vent issue. Try when it dies to break the seal on the cap (i.e. loosen the gas cap). Then try to restart it. How does your air filter and fuel filter look. Have they ever been replaced?

 

[CNBTreeTrimming]

I agree with the tank vent issue. Blow everything off with a compressor to clear the small saw dust. If it's hot it gets much worse as the fuel tries to expand in the tank. I have to crack the tank on my 200's often when it's over 90 degrees and the fuel starts boiling as all the air escapes. Then it's fine for awhile.

 

[grand lake]

Thanks for your help. The air and gas filters are old but have been cleaned. I have blown the saw off with air but not the fuel cap. I will clean every thing again and also put some air to the gas cap from the back side. It does seem to get worse as the saw reaches operating temps.

 

[galde]

Another possibility is a break in the fuel pickup line in the tank. If a leak is below the fuel level it won't be apparent, but if the fuel level goes below the break the carb will suck air just like with an empty tank. I test this situation by having just enough fuel in the tank to cover the fuel filter and I disconnect the fuel line at the carb and attach a clear line a couple feet long to the fuel line. With the other end of the line elevated above the saw I carefully draw fuel up the line and observe how easily it comes ( checks for clogged fuel filter ) up and goes back down, and I look for air bubbles (checks foe a break in the line) .

 

[sefh3]

Cracked fuel line or cranked impulse but more than likely fuel line. Take the fuel like off and make sure there are no cracks in it.

 

[fearofpavement]

Could be something as simple as the filter not falling to the front of the tank when tilted. A stiff line or one that is too short or two long can cause this.

As far as narrowing it down, it is not likely to be a carb issue as the saw runs well in some positions, it probably isn't an air leak as they have a different symptom so if it is a fuel supply issue it pretty much has to be:
a leaky hose
fuel filter not submerged at some saw angles

Not sure I buy the vent theory as it seems like it would not be position related. If the tank isn't venting, it will cause problems no matter which direction the saw is tilted.

If it was my saw, I would replace the hose going between the carb and the fuel filter and see what happened.

 

[Fish]

Considering that the fuel lines on this model are notorious for going bad, that is the first thing to check. Take off the air filter cover and look at the fuel line and all of the cracks, if so, replace the line and rebuild the carb{go through}.

 

[Stihlofadeal64]

Considering that the fuel lines on this model are notorious for going bad, that is the first thing to check. Take off the air filter cover and look at the fuel line and all of the cracks, if so, replace the line and rebuild the carb{go through}.

+1 for me. The gas line is usually about $8.00 or so at the dealer here. Replace it as an inexpensive first line and while you have it off check your carb. The kits for them are about $9.00 here as well. Make sure the carb is clean before you put the kit in it.

 

[m2theb]

Could be something as simple as the filter not falling to the front of the tank when tilted. A stiff line or one that is too short or two long can cause this.

As far as narrowing it down, it is not likely to be a carb issue as the saw runs well in some positions, it probably isn't an air leak as they have a different symptom so if it is a fuel supply issue it pretty much has to be:
a leaky hose
fuel filter not submerged at some saw angles

Not sure I buy the vent theory as it seems like it would not be position related. If the tank isn't venting, it will cause problems no matter which direction the saw is tilted.

If it was my saw, I would replace the hose going between the carb and the fuel filter and see what happened.

i agree here, 9 years later.
dealing with an 026 with a new oem fuel line, which is short and is stressed putting on the filter.
same issue, point it down and it wants to stall and does sometimes. Otherwise, runs fine and strong in the cut.
no air leaks, no line leaks,
it’s a funny, dangly fuel line and being new is somewhat stiff.
I could put a longer fuel line from a later model, but would need to enlarge the hole in the tank.

 

[HarleyT]

Dang, that "Fish" guy was brilliant!!

 

[wcorey]

As is typical the op never followed up on what fixed it, (if anything).
My bet would be/have been fuel puddling in the intake boot area and in this recent case I think 026's are sort of known for it.

 

[SteveSr]

Dang, that "Fish" guy was brilliant!!

One of your alter egos?

 

[wcorey]

One of your alter egos?

That would be an affirmative... One of those 'the artist formerly known as' sort of deals...

 

[SteveSr]

i agree here, 9 years later.
dealing with an 026 with a new oem fuel line, which is short and is stressed putting on the filter.
same issue, point it down and it wants to stall and does sometimes. Otherwise, runs fine and strong in the cut.
no air leaks, no line leaks,

These are known for fuel pooling in the intake. Pointing the nose down throws a slug of fuel into the engine causing the idle speed to drop and/or possibly stall. The fix is to lean out the "L" screw until the problem goes away.

it’s a funny, dangly fuel line and being new is somewhat stiff.
I could put a longer fuel line from a later model, but would need to enlarge the hole in the tank.

The new longer hose is s worthwhile upgrade.

 

[Kenskip1]

How about forgetting the tank vent. he says the saw runs fine. I am thinking about something floating around inside the carburetor. When he tips the saw the debris is now clogging the passageway for the gas. Yes this could be a long shot.

I have been thinking. How about water in the gas tank? As the gas filter is mixed with water, we all know that water is heavier than gas, the saw will not draw it up. Yes I know this is another long shot, but what the hay!