Hot Topics: Chainsaw Won't Start

hands working on chainsaw's forums feature 250,000+ expert and novice discussions in over 120 categories, so we highlight popular chats to help with related projects. This transcript has been lightly edited.

Original Post: Poulan Chainsaw - starts but won't run

pigfanatic - Member

Help - Let someone borrow our chainsaw and now it will start but will not run. Read some of the other post and have replaced the sparkplug and cleaned the airfilter.

We also loosened the gas cap, started it up and it would run. Press the trottle and it would shut off. The longest it has ran was about 30 seconds (and only once).

Now what? Thanks so much for any and all help.

ChrisHarris - Member

This is why I won't loan power tools to anyone. Is it possible that whomever you loaned it too didn't mix oil in the gas when running it? The piston could have gotten hot enough to do damage, but not hot enough to actually seize it to the cylinder.

Sounds like a carb problem though. Try taking the carb off and put a new gasket kit in it. Pull the welch plugs and replace the filter screens. Replace welch plugs with small punch and put a drop of clear fingernail polish around them when you punch them back in. The polish acts like a thread locker to keep the welch plugs from, coming out. Wipe off excess after installing the plugs.

Best way to get the old plugs out is to punch them with an awl and then pry them out.

Pay carefull attention to the gaskets when you take them off. There are two gaskets on each side. The side with 4 screws--the thick gasket goes on first and the thin gasket with the metal washer on it, goes on last. The side with only 1 big screw--thin gasket goes on first, followed by the thicker one. Don't over tighten screws. The gaskets are soft, and so is the aluminum.

Replace the main jet too. It's included in the kit. The jet is under that gasket with the little metal washer on it. There is a little fork-shaped piece of metal that pivots back and forth on a small shaft. There is a small Phillips screw holding it all together. Be careful when removing that little Phillips screw. There is a tiny spring under there, and it usually ends up flying across the room if your not careful. Good luck finding it, if you drop it. Now pull the jet out and just drop the new one in.

If a carb kit, and some adjusting won't fix it, your probably going to have to take it to the local shop.

To adjust carb:

Carb will have an L and an H stamped on it. High speed needle and Low speed needle.

Adjust the high speed first:

Run the saw up to full throttle and turn the H screw in (Lean) untill saw reaches max speed and then slows down. Now back the screw out again the other way untill the saw picks up speed again and then slows down. That will be just slightly rich. You want to run it a bit on the rich side because when you sink that chain into a log and put a load on the saw, it takes more fuel to keep it running. If you just tune it for max speed and cut logs with it--you'll be running it too lean, and cook it.

Adjust the low side next:

Same as high side. Turn the L screw in and listen to the saw pick up speed. Turn it in about 1/4 turn at a time untill you hear saw slow down or maybe even die. Now back the screw out about 1/4--1/2 turn and check throttle response. It should be snappy. Engine should idle well for at least 30--45 seconds and then snap to attention instantly when you give it full throttle. It is stumbles and stutters when you throttle up--it's still a bit rich. You can lean the L needle about 1/8th turn at a time untill it's nice and smooth on transition.

Go back and double check the H needle to make sure it's still a little rich. Adjusting the L needle has an effect on the H needle, so be sure and doublecheck the H needle after you tune the low end.

You may have to adjust the idle screw after tuning the L needle. If the engine was overly rich, and you adjusted the low nedle, it will make the idle spped up. Just back that big screw (with the spring on it) out untill it idles at the speed you want. Usually slow enough that the chain won't turn when the saw is idling.

Troy B - Member

poulan pro?

I have one pp4218av did the same thing loaned it out had the same problem check the return springs for the linkages that controles throat plates i'll bet one is broken that is what i found with mine even if you didn't loan it out it would have probably happend to you if that is the problem good luck in search of new spring for mine

cheese - Forum Topic Moderator

I believe I'd start by opening the mixture screws a bit, and readjusting them. Actually, I'd probably start by changing the gas to be sure it has fresh gas with the proper oil mix in it. Then if there are still problems, go to the mixture screw. Sometimes opening them up and readjusting them allows a bit of trash to flush through and clear up the problem.

Quick-Silver - Member

I realize this is an old thread, but maybe you guys are still around to answer my question.

I need to know the factory settings for the H and L adjustments. My saw will not start and I know the adjustment screws have been changed from the factory settings. My saw is the Poulan Woodshark P3314 WSA 802046 S/N 06198D301478-2 (06:50), 42CC:EM


cheese - Forum Topic Moderator

Turn them both in until they lightly seat, then back them out 1 turn each. Then start it and adjust the L screw for best idle and crisp throttle response. Rev up all the way and adjust H screw until it revs the fastest, then back off the screw until the saw begins to flutter a bit. From there you may have to go back and fine tune the L screw.

jgavrile - Member

Poulan idle mixture screws --special tool need?

Just where do you get a special tool to adjust the 2 mixture screws on a Poulan chainsaw?? They both are not the same type?? One looks like it has a security pin in the middle?? I am having trobuble with it running at high speed. It want to stall. Idle and low speed are fine

Gronk - Member

Join Date: Aug 2009

Posts: 2

Received 0 Votes on 0 Posts

chainsaw won't stay running

Fuel cap vent is plugged. That's why you hear the hiss of in-rushing air when you open cap. Engine has sucked a vacuum into tank, eventually starving fuel flow.

Completely disassemble cap and drill out or punch out tiny center breather hole. Assemble and install cap.

cheese - Forum Topic Moderator

Do not follow that advice. You risk setting yourself on fire this way. You probably need to open the high speed screw a little bit. There are often times caps that pop onto the screws that limit them and you can remove them if necessary. Sometimes you have to use a pair of very thin needle-nose pliers to turn them. Some can be turned with a blue electrical butt-connector pushed down over the head of it.

Gronk - Member

poulan chainsaw won't stay running

Ha! There's a one-way, rubber check valve inside the cap to allow air in and keep fuel from escaping. Sorta looks like a nipple on a baby bottle. You need to remove the tether retainer to get to it. You'll understand if you actually know how the cap is constructed. All that said, if the saw dies while running and there's a hiss when you remove the fuel cap, disassemble cap and drill out the tiny bronze plug in the vent hole.

cheese - Forum Topic Moderator

Believe me, I know how the cap is constructed. I do not recommend drilling a hole in it. If you are disassembling the cap only to clean the vent hole behind the duckbill, that's one thing, but that doesn't sound like what you recommended in the previous post. You said to drill or punch a hole in it. I guess you could have meant to drill or punch out the already existing vent hole? If the existing hole is clogged, just clean it out. No need for punches and drills. Trying to keep it safe here... we get some wacky advice from time to time. I'm sure you understand.

sf_gray - Member

Fuel Line Cracked?

If the other suggestions do not work.

I just fixed a problem with a 2-cycle backpack blower that was doing the same thing. The gas line had cracked. The bowl would fill when you primed it (it was leaking fuel where I could not see it), it would start, but would die when bowl emptied. Fixed line, and issue was resolved.

Also, if it was working well when you loaned it, your friend may have used contaminated fuel, might need to clean the carb.

Denman123a - Member

Did you ever get hold of a tool to get at those adjustment screws? I need the same thing , ...mine is hard starting and won't idle at all, ... someone suggested backing the screws out a turn or two and cranking to clear debris, then return them to original settings, .... I'm getting poor fuel delivery into the motor and can't wet the plug no matter how much priming or choking I do, ... it'll sometimes start on full throttle, usually not even that, ... cheers

Denman123a - Member

Turn them both in until they lightly seat, then back them out 1 turn each. Then start it and adjust the L screw for best idle and crisp throttle response. Rev up all the way and adjust H screw until it revs the fastest, then back off the screw until the saw begins to flutter a bit. From there you may have to go back and fine tune the L screw.

Do you define a turn as 180* or 360*?

cheese - Forum Topic Moderator

360 degrees. Just as a starting point for the settings.

gh0st - Member

Carb Adjusting

Spoke with a Husqvarna representative during a training course.And here is what he said on carb adjusting 2 cyl products.

Reset carb by gently screwing both (H & L)adjustment screws all the way in and they backing them out exactly 2 turns(1 turn= 360 degrees). You should be able to start your product then you will need to idle it up enough for it to stay running on its own.Here is the key you have to let engine warm up approx 4-5 min before making major adjustments or you could end up setting it too lean.

Once engine is warm run at full speed and make you adjustment on the "L" only,then you will need to adjust idle accordingly after.

Person experience: Some older models you will need to reset carb to only 1 and 1/2 turn instead of 2.Then follow the above instructions.

Remember: Often you can mask over other more serious problems by making big adjustments If you have to make huge adjustments after resetting carb and checking fuel system(filter,lines,etc..)then more than likely you have a problem somewhere else.

I have part numbers for some of the carb adjust tools and will try and post them later when I get a chance.

Hope this helps....

cheese - Forum Topic Moderator

So according to the tech, the H screw should be exactly 2 turns out and stay there, never to be moved? I disagree and this can cause problems in certain conditions. For the best performance and engine longevity, adjust as mentioned earlier. You can start with the screws 2 turns out rather than 1 if 1 isn't enough to get it to run well enough to fine tune it.

Airman - Member

One of the best sayings I have heard is, “When everything else fails read the instructions.”

The three leading carburetor manufacturers have websites that includes carburetor adjustment instructions.

Equipment manufactures give carburetor adjustment instructions for the carburetors installed on their equipment.


Service Manuals


USA Zama : Service Tips

Tillotson (my least favorite site) the manuals give complete instructions.


Claw Hammer - Member

Not one of you spoke a word about cleaning the fuel filter and not one of you spoke a word about doing a compression test.

Not one of you ever thought to take it to a repair shop and pay a couple of dollars to a trained service tech that could have probably repaired it for less then $20!

Penny wise and dollar foolish.

If you had a job, you could take the chainsaw to a shop and have it repaired and work one extra hour or maybe two and make more money at work then what it would cost to pay someone to fix your saw for you.

So how much do you really save when you spend several weekends working on the chainsaw instead of cutting firewood?

If you can't fix it, then get rid of it and buy another one.

Walmart and Lowes sold Poulans for $150 - and that was with a spare chain, a file kit and a tool kit and a carrying case!

Airman - Member

Apparently you looked at one of the posts concerning a chainsaw problem not carburetor adjustment.

gh0st - Member

Cheese, I am not arguing with you I am just relaying the info that was given directly to me from the company I work for. I have been adjusting the carbs that way as they requested and have actually seen a drop in recalls.Once again this is mostly on newer products 2008+. (I think the Instructor is playing it safe by having us adjust it a little on the rich side).

Airman, Thanks for the links.

Claw hammer, I am a 2 cyl technician for a major corporation been doing this type of work for about 4 years our labor rate is a little more than twice what you mentioned it would take to repair it. Yes, however at times it would be best to buy a new one,but these forums are for those that are trying to help each other out with what they know.

cheese - Forum Topic Moderator

Normally I would do this in a private message, but since you publicly insulted everyone on this thread, I will state my position publicly as well.

Claw hammer, if you go buy new equipment every time it needs a $20 service, let me haul off your trash for you. That would be what I call penny wise and dollar foolish; spending money on a replacement rather than fixing it yourself. the way... is what this site is about, and what the recent posters asked for (advice about adjusting carbs). Why would we suggest cleaning a fuel filter? Modern fuel filters are not meant to be cleaned, they are meant to be replaced. Also, the original poster never replied to the first advice given, which did indicate there could be internal damage. The rest of the replies were to other members with other questions about adjusting carbs. Finally, what gives you the right to assume the poster is too cheap to pay for a repair or doesn't have a job? You are a disservice to this forum and we would appreciate it if you kept your opinion to yourself. Members who come to this site seeking advice shouldn't have to put up with your type of replies. Thank you and have a nice day.


I'm not arguing's all good. I also feel that 2 turns out is very possibly too rich, which is definitely better than too lean, but not good either. It may reduce call backs, but if it's too rich it will contribute to carbon buildup, which as you know causes clogged exhausts and sometimes cylinder scoring when pieces break loose. I fine tune the H screw for every engine, not just a set number of turns out. I do hit optimum, then go a hair on the rich side though, for good measure. Call backs on equipment I adjusted are rare.

Denman123a - Member

Cheese, I'm not sure if ClawHammer needed to be banned unless he did something elsewhere, but that said he seemed to miss the point of the forum as you clearly said.

I've tried numerous things with my Poulan Pro 4318 AVX except the two full turns as a start setting to get the saw started. I'll give that a shot tomorrow. May be too late anyhow as yesterday I did a compression test and got 60psi dry and 130psi wet, .... my little green Poulan 16" got 140 in two pulls and runs like a champ. More hours on it than the "Pro" I might add.

My conclusion is it's ring time. I got a ring from a local Poulan dealer here who assured me that 1) the "Pro" does not have a two-year warranty as indicated elsewhere, and 2) that he could not sell me a carb adjust tool and that Poulan sold same only to dealers. He also felt that 60 psi was plenty of compression for a chainsaw. I bought a ring from him and decided that I'll deal online with any other chainsaw issues on the basis that I don't need uninvited opinions and unhelpful dealers.

"Tune in tomorrow" for the ongoing saga of the Poulan Pro that WON'T ....

cheese - Forum Topic Moderator

I don't agree that 60 psi is good on any engine.

marbobj - Member

60 psi is only good if you want to plant flowers in it. That is why your saw won't start.

Denman123a - Member

My direct experience with my two Poulan saws leads me to agree with you, and therefore disagree with the dealer who felt 60 was OK, ... as I said I'll deal elsewhere from now on. Ignorance has no place in the workplace. Beer 4U2

arnold123 - Member

i have one pp4218av did the same thing loaned it out had the same problem check the return springs for the linkages that controles throat plates i'll bet one is broken that is what i found with mine even if you didn't loan it out it would have probably happend to you if that is the problem good luck in search of new spring for mine

sidny - Member

carb adj tools

From the discription I think I read, they sound like insert bits or tools. They look like a torx bit with a hole in them. I found them in a local hdw. store in the bit asst cabinet along with the phillips, square, hex etc.

tomax - Member

did you ever find the spring you needed

I know this is an old post but I am in the same situation. I don't know if the spring broke or if there was a locking mechanism that connects to the carb itself which is now. missing. There is a slot on the carb that looks as if something should go there to lock the spring. ???????? any help out there????

hopkinsr2 - Member

I'm not real familliar with the 4218,, But the Poulan website Poulan Pro - Poulan - Weed Eater - McCulloch - User Manuals has a parts look-up that may help you... Roger

tomax - Member

Thanks for the reply however I think that the carbs on these things are so cheap that they don't even make repair parts for them.

dowjim1 - Member

wont stay running without choke

my problem is that the saw starts and runs with the choke out but revs and dies when you take choke off. Carb set 1 1/2 out on both needles.

cheese - Forum Topic Moderator

Hello dowjim1,

Your carburetor needs to be taken apart and cleaned, possibly rebuilt, and check the condition of your fuel lines.

ksdhillon - Member

Chainsaw would run for a minute then dies

I have a Poulan Pro 255 that would start ok but die immediately when I gave it gas, just like others have experienced. I tried removing the air filter since it was not very clean but that did not have any effect. I have owned the saw for about 15 years and admittedly did very little to maintain it because it always ran great. Once it started acting up this spring I followed the advice in this forum (which I should have done anyway a long time ago!); I bought a carberator kit, which was actually a whole new carb ($20).

I also replaced the air filter, spark plug and fuel filter. When replacing the carb I noticed the fuel line had become brittle so I replaced that also. If you are going to the trouble of cleaning/rebuilding or replacing the carb, you should do the fuel line as well, as it was only a buck or 2. Tough job getting the fuel line through the gas tank housing... After I did all of that it starts on first or second pull and runs as good as new. No carb adjustments were required other than setting the idle. Less than $30 - 35 and I have a saw that runs as good as new.

Good Luck

master1 - Member

mcculloch similar problem

I've been having a similar problem with my mac 3200.i cleaned and rebuilt the carb. and changed out the fuel lines/filter because they were falling apart. i can get it to start, but it stalls if i throttle up. i got it to get up to speed if i very gradually pulled the throttle. i noticed the gas flowing thru the primer bulb, but not the main intake line. could there still be a blockage or could it be a vacuum leak. thanks for any info on what else i can try.

cheese - Forum Topic Moderator

Did you try backing out the high speed screw a little?

master1 - Member

i just tried that, it kicked over then stalled again, it's probably out about 2-2 1/4 turns now. i don't see any fuel coming thru the line from the tank to carb. i just made sure the line from the carb. (throttle side) was going into the side of the PR. bulb marked "in" and the other line to the tank. is this correct? does the return line need to be submerged to work properly?

DougChemist - Member

Running fuel lines on chainsaws / weedeaters

Here's a trick I learned from running HPLC lines. Cut the line at an angle.




But make the angle longer (30 degrees) than pictured. The angle should be shallow enough to thread it through the hole with a little excess.

Put the end cut through the hole and carefully pull it through with long needle nose pliers. Some tubing comes precut as shown above.

cheese - Forum Topic Moderator

The return line only has to barely enter the tank. Sounds like you have it routed correctly. Is the fuel filter stopped up?

snrusnak - Member

I have something similar going on.

My boss recently gave me a poulan pro 295 20" saw, and the clutch cover/chain brake was melted from the exhaust. He said it's the second time it happened so he wanted to get rid of it. I figured I could weld an exhaust shield on it to keep it from happening again (I think there was one there originally and it broke off). So I did that and replaced the clutch cover/chain brake it was like $20.

The fuel line was ripped so I replaced it, and the carb kit was only $4 so figured I'd do it as well so it was all running good. The carb was VERY simple, one solid, machined pieced of aluminum with a "cap" on each side. I replaced the gaskets and cleaned it up (wasn't really dirty anyway) and put it all together, still need to replace the air filter. So go to start it and it fires up eventually but doesn't stay running. I decide to start messing with the two screws (I assumed one was low one was high). Got it to start right up and idle fine but under gas it'd die. Eventually got it to where it's running good just by screwing with it. I just wanted to say thanks for the information in this thread because I'm sure I don't have it adjusted perfect so when I run it again I can follow the steps above to properly adjust it. So for about $25 I have a decent saw...