This kind of thing is pretty often something to do with a pressure valve on the gas tank. Simply put, you run it for awhile, and it vacuums itself out of gas. New valve = new saw.

One more simple thing.....When it stops, how tight is the chain? Can you move it by hand, with gloves?

Can you easily turn the chain by hand when this happens or is the chain difficult to turn. Wear your gloves when doing this.

thanks for the quick response. the chain is movable but not easily...the chain oil comes out automatically and I am not certain there is enough.

Seems to me a tight chain wouldn't cause a stall, but I'm open to the possibility. Explanation on that?

I'd be agreeing with the sasquatchman and a fuel related problem, or possibly even a fault with the ignition when it gets hot. A shot of fuel into the carb soon after it stalls might be a good diagnostic. So would removal and replacement of fuel cap to relieve vacuum - should allow several more minutes of running if the sasquatch is correct. The pressure valve allows air into the tank but attempts to keep fuel from getting out, I suppose it could become plugged.

Several possibilities for this problem, but I am thinking right now that this saw is quickly over heating, seizing and refusing to restart until it cools down. Again it may not be the problem but one possibility. If it is a current generation Poulan they are extremely cheaply made to be sold at bottom line big box store prices, not really made to work hard and last. These are throw aways after a very limited time in use. There are also many other possibilities but the saw if of current generation is probably not worth the time, money and effort.

Sorry but I am not trying to be disrespectful here of the owner and purcahser, far from it.

You might have intermittent ignition coil. Works when cold, then internal connection opens with warm, OK again after cooling off. Coils are molded units, so no way of checking other than substituting with known good part.

Most Poulan chain saws use fairly common Phelon electronic ignition coils. Should cost about $25.

It is possible that the ignition is at fault, but doubtful.
It is most likely fuel/air related. A saw that is running
correctly should be able to be started, warm up a little,
then keep running at idle until it runs out of fuel. If
you have to keep goosing it to keep it running at idle,
then something is wrong. Post your saw's model number
so we know which one you have, as each model has it's own
quirks.
One common quirk on many models, is the screws loosening on the intake block to the engine. Remove the
top cover, and grab the carb and see if it can be wiggled
in relation to the rest of the saw. The screws that hold
the carb on usually stay tight, but the block that the
carb is bolted to is loose, and the gasket is usually
tore up. Just something to check for.
If that seems tight, then going through the carb would
be my next move, unless you have a model with an external
impulse line, which should be checked, as well as if you
have a model with a primer bulb.
But otherwise I would look inside the carb.

Fish

I have a Poulan Chainsaw rebadged as a McCullock here in Australia.

I had numerous problems with it all fuel related.
Really it was a matter of tuning the carby but Electrolux refused to sell me the tool to do so, so I made my own and then found they were available as an aftermarket item.

One of the biggest problems was that I would use it for a few minutes and then go to idle and it would stall and refuse to start till it cooled down.

The problem was it was running to lean and over heating. Once I adjusted the carby it was fine.

Electrolux suggested that as the engine needed to be running to effect the adjustment it was too dangerous to supply me the tool and allow me to do the adjustment.
I took this as an insult as I had been doing just that for forty years. They said take it to a dealer and he would do a tune up free of charge. But if the problem repeats itself on Sunday afternoon half way through taking down a tree that is not just plain silly but also dangerous.

Look up "McCullock chainsaw tool" for the postings and you will find instructions in making the tool and a source where you can buy one.

Next time buy a Stihl I know I will be.

Regards
Dock.

Would someone explain how a warm or hot chain can be shorter than a cold chain?
Mike

Almost everyhing (certainly metals) expands with heat. The expansion makes the chain longer. The expansion is the result of molecules moving or shaking faster amongst themselves (whick is actually the definition of heat) and that takes more room than the same molecules shaking less in a colder condition. Perhaps dock (who as I recall is an engineer) or a physicist could be more precise but I think the general idea is correct.
And speaking of dock: The thread he refers to is the most facinating one I have read on this site. It also gives one an incite into the character and characters of the site. Give it a try

Had a similiar problem with a Poulan 2450 several years ago. Turned out to be a plugged up muffler. The screen inside got plugged with carbon.

Good point from mla2ofus. The bar also gets hot and expands. The chain and bar might expand at different rates and sizes.

Today I experienced a similar problem with my Husqvarna 345. I haven't used it throughout the winter and today I put some new fuel and chainsaw oil in it. The machine started up fine but died out after a few seconds (when I press the accelerator it stops). Does this sound like a fuel problem?

Sounds like a partially blocked pickup body in the fuel tank.
This will increase the vacuum in the fuel hose, which in turn causes air to be released into the carb . End result? Vapor lock.
Change the pickup body.

I am having the same problem with my husky 350. Saw runs for a few seconds then stalls. I already checked the fuel filter and gave it fresh fuel. Giving it throttle only chokes it out. Could it be a bad fuel pump diaphram?

One more thing ... I also removed the fuel filter and tried rinning it without the filter. Also didn't fix the problem.

IMO you have to deterimine if it's fuel or ign problem. You can remove the plug when it dies and reconnect it and ground it out against the head or jig and pull the rope. you should see a pretty blue spark??? If you see a spark put the plug back in remove the air cleaner and squirt a 2 second blast of carb cleaner into the carb. opening. It should fire immediately off the carb. cleaner. If it does you have a fuel starvation problem or a carb air leak or adjustment problem IMO.

Yeah. Probably a fuel starvation or air leak. The thing I can't figure out is what caused it. The saw is like new and ran perfect last time I used it.

i have a stihl 290 model. it has the above described problem. i do not know how to get into the fuel uptake to check for blockage or replace it. i had the fuel line replaced last season. i had the carb kit routine done last season as well. i also dont know how to check the vent int he gas tank. it sounds simple enough but so far i havent found anything. thanks

Hi Folks,

I'm having a similar problem with a Poulan model PP4218AVHD. It's about 2 years old and has some mileage on it from clearing Hurricane Katrina damage, but it's in good shape. It starts like a champ and runs fine for 20 minutes or so of tree cutting. When it dies, it will NOT restart until it's fully cooled down. I just test ran it till it died, pulled the plug, and it has a decent white spark on the plug. Is this indicative of a good coil or should there be a strong blue spark? Also, the plug is dry. Does this indicate a fuel issue? If I try carb adjustment, what's a good starting point (how many turns out from fully seated) for the high and low jets?

Thanks,

Dan

I would mark where the screws are now and count the turns in say 1 3/4" to seat lightly. I think most saws start out at 1 trun to 1 1/2 turns from seated. But, it's alway good to know where the carb. was adjusted just in case turning the Hi and Low screws does nothing. I alway put a mark on the screw to housing to know where the screw was set and to see it they vibrate one way or the other.

Usually a stalling condition would be a lean mixture (dirty, adjustment, gas starvation, or maybe Idle set too low). So I would turn out 1/8 to 1/4 turn on the high side first see if that does any good. Another problem is prolong storage the little passages get gummed up. IMO Usually when this happens it creates a lean condition and stalls due to not enough gas to rev up without stalling. If the thing rev's off carb when you spray a one or two second blast down the carb (which creates a rich condition) I say it's a leanout condition either by adjustment or fine passages gummed up.

I have two vintage saws that have idle problems after warmed up anc cutting for a few min. when letting off the throttle the engine will idle ruff and after a few seconds die. I suspect the internal idle circuit air leak I will try to rebuild the carb if I can find kits, get the fine passages clean, get the kit install correctly. This also creates a hard starting condition. so if anybody can help with hot idling problem I would appreicate it.

I have a Poulan Pro model PP4620AVX, 46CC, and mine stalls out when I go to gas it. I worked fine first year, now it has the same problem as others.

I also have a Poulan chainsaw, and had the same problem. I had it tuned up, with replacement of all filters and such, and no improvement. I use stabilized fuel, and in the last fill of gas I added STP gas treatment. No improvement. Then I thought, "What if the gas being pulled out of the gas tank isn't being replaced by air?" So what I did was loosen the gas cap and retighten it. The problem disappeared completely and immediately. Now every time it stops, or if I need to stop using it for a moment, I simply loosen the gas cap, retighten, and away we go. It purrs.

Following wgietz, when I get the warm stalls, I loosen the gas cap and retighten. Chainsaw then works just fine. Thanks wgietz

Clean the vent hole within the fuel cap will save you the need to remove the cap every 5-10 minutes lol .

I also have a Poulan with the same behavior. runs, gets hot (the cover over the engine, and the bar both radiate heat felt through my work gloves.
I did a quick search and found another forum with small engine experts.

Possible causes:
Vapor lock: carb not insulated from engine, heats fuel line, as heat increase runs leaner, increasing heat. stop with vapor lock in the fuel line.
Test: Loosen gas cap and retighten, then restart.

Clogged fuel line or filter:
Test: clean or replace filter and lines.

Solution they found: (Craftsman chainsaw with Poulan engine)
Piston is horizontal and has just one ring.
Test: compression before cold start then again after hot stall.
Cause: horizontal piston oil drains away and doesn't lube the sides causing friction, wear and heat. worn ring increases gap end when hot and loss of compression causes stall.

Anyone want to buy my one year old used Poulan? :-(

Sorry Names Tucker...Not Sucker !

I have the Poulan saw and it cuts out after about 2-4 minutes. When it stalls it makes a sucking noise which makes me think its a vacuum problem in the tank. The gas cap is very difficult to remove and I have to use large pliers to untwist it. I've fiddled with the idle setting and high setting but no improvement. Any ideas?

Hi Folks, I have a Sthil 250 and my problem is it runs for about 20 min then dies and will not crank for at least a week or so. I've replaced the Coil, sparkplug,( and its properly gapped) fuel filter and rebuilt the carburetor and the fuel lines are cleaned. I've changed the fuel out also. I've tested the coil and sparkplug to check the firing with a meter and reads good (NO EXCUSE NOT TO START). HELP Please

Ensure fuel cap vent is unobstructed !

Its good, thanks for responding.

Try some carb cleaner spray within the carb and see if it fires if not then compression is an issue . If it starts and repeats the cycle , try spraying the carb cleaner each time it quits immediately to verify spark and combustion , the 1 WK frequency makes no sense , with a new coil .

Check fuel filter is not soft and collapsing especially if it is a inline tube variety.

Op has replaced fuel filter tricky !

Well I started reading this thread in 2006. Musta gotten blurry and missed that. Sounds like a case vacuum leaking down or a case pressure leaking down. How is the impulse line?

Apparently new also . A valid compression test would go a long way . The 1 week between starts makes little sense .

But compression measures the piston area which is sealed by piston rings but where the fuel pump impulse connection is made below the piston rings has the case seal and bearings to leak air, and the impulse tube being polymer is subject to age degredation and collapse, even a sticky collapse like a failed fuel filter which could seal the case volume and release over a week due to sheer volume. The 1 week thing is curious.

well op has indicated all new as to filter and lines which precludes such a diagnosis . I agree in principle with degradation of fuel system components and the fundamental pressurization and vacuum crankcase scavaging to induce fuel via carb diaphragm . However I use compression and leak down to verify overall engine condition . You may well be right that crank seals or gaskets could be compromised . Thus my advice to fog the engine with some carb cleaner . Op has not gotten back to us since Monday , apparently has moved on lol . Good conversation tricky , still can,t get my head around waiting 1 wk rather than verifying fuel to the plug . If not then pursue why , as you have indicated .

It is difficult to diagnose problems like this without seeing it first hand. However the problem sounds like Fuel starvation.Suggest you check the following.

!. Check the breather on the fuel tank to make sure it is not blocked. It is usually found in the Fuel Tank cap.

2. Check that the choke is operating properly.

4. Check the exhaust to make sure it is not blocked even Partially..

Hope this helps.

Dock.

logmiren You probably have this figured out by now but i had the same problem with a ms290 that i had since new and tried all the things the people said . Turns out the cap does not vent because its on the side. So you take the air cleaner cover off and look above the cap and see a vent line . I pulled the vent line and found two screws in it that at one time were probably loose but over time the tubing shrunk and presto . No venty. I just removed the and it purrs like new now.

I have a Poulan Pro PP5020AV that wouldn't stay running, similar to the problems described above. The saw is less than two years old. Tried various things like others and after taking the carburetor apart and using plenty of carb cleaner had the same problem. Got it to run briefly by shooting some carb cleaner into the intake. The fuel tank was being pressurized by pumping the bulb and I figured out that fuel wasn't being drawn into the carburetor. Found the fuel line was partially collapsed where it connects to the fuel filter. Looked like someone forced it on and damaged the fuel line in the process. Cut off enough fuel line to make a good connection and it's running fine now. One more issue to consider.

Good find Bud !