# Poulan 18" 40CC chainsaw stalls under load



## ducowti (Dec 31, 2007)

Got it new. Unit worked fine for the first hour or so, then began stalling under load (i.e. as I applied the chain to a tree it'd bog and die). I removed the bar and chain today and it'll go like hell w.those removed, w.only the flywheel/sprocket spinning, but when I reattach the bar/chain - even very loosely - it bogs. 

There's no other apparent problem - fuel lines ok (not split), nothing else overtly going on. I wouldn't think it's a carb issue since it happened so soon after first use, but what do I know?!  Don't think it's an air leak either - the 4 bolts underside are tight and secure. The brake is not on and works properly. 

Any ideas why it's bogging and dying? Again, it only does this under load. 

thanks!


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## 30yearTech (Sep 14, 2006)

Sounds like it's running too lean, could be a carburetor adjustment, or it could be an air leak. If it's one of the new "strato charged" designs they are set to run very lean from the factory and it could just be that since it's had some run time it needs a little adjustment.

If this saw is new, I would suggest taking it in to a warranty repair facility and let them check it out for you.


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## ducowti (Dec 31, 2007)

30yearTech said:


> Sounds like it's running too lean, could be a carburetor adjustment, or it could be an air leak. If it's one of the new "strato charged" designs they are set to run very lean from the factory and it could just be that since it's had some run time it needs a little adjustment.
> 
> If this saw is new, I would suggest taking it in to a warranty repair facility and let them check it out for you.


I got it at Sam's new, but out of the box. It was unused but I shoulda known. Tried to save a few more bucks  They wouldn't take it back as such and by the time I motivated and tried to get it warranteed it must've been out of warranty so I was SOL. Cost of inspection at a repair shop will be at least an hour and I'm already at least half way to the cost of new. Anyway, it's gotta be 3 yrs old by now (maybe 4?) so I don't know about the strato bit. 

I'll try to monkey w.the carbs, make some adjustments. 

As for air leak how would I know for sure, besides taking it to a shop for them to test? Is it something I can do at home? I do all my motorcycle work so at least I know how to turn a wrench.


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## 30yearTech (Sep 14, 2006)

Do you know the specific model number of your saw?

Some models of Poulan chain saws have fuel pump pulse hoses that can cause air leaks and or rubber intake manifolds that can leak as well. You should also inspect the fuel fuel filter and fuel lines to make sure there are no leaks and that the fuel filter is attached to the pickup line. A 3 year old chainsaw can have carburetor issues even if it has only been used less then an hour, once fuel has come in contact with the components inside the carburetor, there can be problems with diaphragms, and metering circuits, needles & seats etc...


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## ducowti (Dec 31, 2007)

30yearTech said:


> Do you know the specific model number of your saw?
> 
> ...A 3 year old chainsaw can have carburetor issues even if it has only been used less then an hour, once fuel has come in contact with the components inside the carburetor, there can be problems with diaphragms, and metering circuits, needles & seats etc...


SM4018. The problem began pretty much when it was new so it's def not an age-related issue, though age (old fuel, aged bits, etc) is exacerbating the problem and maybe causing more.


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## 30yearTech (Sep 14, 2006)

After looking at a breakdown of your saw, the only place I can see where there may be an air leak would be the insulator between the cylinder and carburetor. Check to make sure this is tight and you should be alright. 

I think that if you open up the load adjustment or high speed adjustment about 1/4 turn (counter clockwise), it may take care of your problem. Since it appears to be running good with no load, opening up this adjustment should give it the extra fuel it needs for a load. The high speed or load adjusting screw is marked with an "H" and is the one located closest to the back or air intake area of the carburetor.

Best of Luck... :thumbsup:


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## ducowti (Dec 31, 2007)

30yearTech said:


> Check to make sure this is tight and you should be alright.
> 
> I think that if you open up the load adjustment or high speed adjustment about 1/4 turn (counter clockwise), it may take care of your problem.
> Best of Luck... :thumbsup:


Thanks for your help. I'll do as you suggest and let you know how I make out.


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## ducowti (Dec 31, 2007)

ducowti said:


> Thanks for your help. I'll do as you suggest and let you know how I make out.


OK...so 45' of tinkering and rocking my low back yanking on the mothergrabbing pullstring and manipulating set screws it's no better off  While I had it WOT I set the H screw and then adjusted the other screw next to it according to pitch of the engine. It got higher and spun higher as I adjusted so I thought it was going to fix my issue. Put the blade to a tree and same thing happens, bogs down. 

I am DONE w.this thing!! :freak:


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## newz7151 (Oct 15, 2006)

Is the chain on backwards? Is the chain brake accidently engaged?


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## ducowti (Dec 31, 2007)

newz7151 said:


> Is the chain on backwards? Is the chain brake accidently engaged?


I guess the chain could be on backwards  I'd feel really stupid if that were the case. I'll check another saw for chain direction. Brake isn't engaged either though it kind of behaves like it may be - i.e. it's slow to get going and then drops quickly when off the throttle.


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## hankster (Jan 1, 1998)

Just because the saw turns faster with the carb adjust does not mean it running correctly... in fact it most likely is running too lean. Start with the carb screws out 1 3/4 turn from fully closed and adjust from there... the final adjustment should be no more then 1/4 turn from that position.

My suggestion is to take it back to get it fixed under warranty. You can void the warranty by working on it yourself.


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## cajunh2s (Apr 19, 2007)

make sure the chain is sharp also....when the saw was new...if you came out the gate
sawing a lot of wood...it wouldn't take long to dull it...

a saw running great with a dull chain won't cut worth a darn...great investment is a chain file...and sharpen to correct angles....keeps mine throwing chips of wood
on a steady base

cajun

cajun


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## paulwest (Aug 11, 2004)

Sounds like a crank seal to me--but theres a lot of little things that cause the same problem. Iv seen this on brand new saws.


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## Stann (Sep 1, 2020)

Hello.
I'm encountering problems similar to those described here which lead me to this post.

I had just thoroughly cleaned and completed making several repairs to a (Poulan 2300AV) chainsaw and got it to the point that it would start up on three or fewer pulls. It seemed to run well, for the most part, but when making a cut, it would bog down and stall under load. Troubleshooting, looking at potential solutions I found both elsewhere and in this very post, by process of elimination, a carburetor adjustment seemed to be in order.

I'm generally a little uncomfortable with adjusting small engine carburetors but as I had a very clear, thorough, step by step procedure outlined in the owner's manual for the exact model, I proceded anticipating no problems. 

One of the very first steps is to "Start the engine and allow engine to idle three minutes to warm up. The engine must be at operating temperature for proper adjustments to be made."

I easily started it up, placed it "on a solid, flat surface" (the ground) to let it idle. As it approached three minutes, it suddenly died. (It was not out of gas). I could not restart it with choke in any position.

"...for proper adjustments to be made." "The engine must be at operating temperature" ..._and running!_

In an attempt to get it started, running, idling again, I tried slightly turning "idle speed adjustment" a little this way ..then that ..nothing. On second thought, it probably should be the "low speed mixture adjustment" instead, so a little turn this way, then that ...nothing. Back and forth from one to the other without keeping accurate track of how many turns, in which direction etc. I have now lost all reference points and am completely lost.

I'd now like to "start with a clean slate". In the past, in reference to other machines, I've seen instructions, for example, to "tighten the X screw in completely, then back out exactly 1 1/2 turns..."

Might someone here know or be able to direct me to where I can find a description of the starting points for this machine?

Thanks in advance


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