Small engine questions: Chain Saw type!

[TopCatGr58]

Hey Folks,

I got a little Poulan Woodshark 14" home/hobby chainsaw several years ago, and had taken decent care of it, would start fairly easily and run strong for many minutes at full rpm cutting some large tree sections and such just fine.

THEN the B-I-L loaned it out to one of his friends who used to work on a tree surgeon service! The borrower said he only used it on firewood... yeah right!

Anyways, got it back and the primer bulb was bad, replaced it, and some fuel line, got it to run, but would not run at full rpm for more than a minute before it would act like it was running out fuel! Knowing how finicky OUR bikes/carbs are, and this thing also has a carb, I ordered a carb kit for it, pulled it apart, NO float, just a spring loaded needle valve assembly, some fancy membranes that I think act like reed valves, as well as a rubber type fuel PUMP diaphragm, also the fuel inlet steel mesh screen. Put it all back together.

Still same symptoms, but also noticed that the prime bulb seemed much harder to push in. Swapped the 2 fuel lines going to the carb...1 from the bulb, and 1 from the tank, and it seemed like it behaved a little better. I then pulled the FILTER off of the end of the fuel line just in case the filter might have been a little clogged( although I did test blow thru it, wasn't breezy easy to blow thru, but I could?). The Engine would still run at full throttle for 30 seconds or so, but then when I would back off and try to give it just modest throttle, it would sound like it was running out of fuel again and die!

A friend of mine said that these consumer type devices were only built to last a short while....that the last 2 numbers of the model # would indicate the estimated # of hours it could be expected to run?? Mine is a 1950, so theoretically that's only 50 hours???

Question#1, anybody hear that hours lifetime description, or urban myth?

Question#2, My friend also said that worn rings will give similar symptoms, ie. hard to start, won't run very long etc.? This engine is a 2 stroke, any other suggestions of what I can do diagnostics wise to try to get it to run and keep running? I had the air filter OFF during the above tests so I could see the clear fuel lines, see if they were flowing or getting bubble/air locked, etc.!

Thanks in advance! I'm trying to get this thing both ready for possible use after SANDY's rath, as well as wanting to do some chainsaw sculpturing on the remnants of the 15 y/o will stump I had to pull due to root rot and breakage, leaning of tree over driveway!

T.C.

[BA80]

Those small 2 stroke engines don't run well without the air filter. Just like the XS if you remove the air filter or put pods on they will run lean.

Try putting 2 fingers over the carb intake and check it adjusting the airflow with you fingers and see if you can keep it going.

There should be 2 small screws in that carb for fuel adjustment. One for high RPM and one for low. They will be marked "HI" and "LO".

[jwhughes3]

I am not professing any expertise on chainsaws, but I bought mine from an older man who scavenged up nonrunning chainsaws as a hobby and rebuilds them and sells them.

He told me if you keep the right mix and fresh gas its very hard to kill these. Most people leave gas in from season to season (like our bikes) that kills them.

Maybe the guy ran it without the right mix, though as a pro it doesnt make sense, and cylinder is worn.

You could check the clutch isnt sticking...

Good luck with storm.

John

[pete_s]

The only other thing that will make it run lean is leaking crankshaft seals(sucks in air) spray starter fluid at the clutch/sprocket to see if it revs up. The mag side of crank, I don't know how to test.

I have also seen those weighted fuel strainers clog and the in tank hoses rot and collapse.

As far as compression go's, if the pull cord is easy to pull now than when it was new, maybe the rings are worn, but I doubt it with the new 2 cycle oils.

[CaptonZap]

Those little carbs are finicky little beasts, and it sounds as though you may be having fuel pump problems.
The diaphragms have to have the little fingers, that act as check valves, have to lay perfectly flat against the body, and if they have been stored so that they have any bow to them, they will give you problems.
As BA80 mentioned, back the HI needle out a little and try again, with fresh gas mix. Keep backing it out until it runs continuously, then full throttle and screw it in till it starts to bog. Back a bit, till it has full song, and you are there. I have run them (Homelite) a lot longer then 50 hours. Wore out 3 or 4 chains before I had to get another one. Went through 4 or 5 saws over the years. (Construction work)
After you get it running, can you keep it running by pushing the prime button? That would indicate a fuel pump problem. And, FRESH GAS! CZ

[trdriver71]

I could also be the spark arrester in the exhaust which is just a mesh screen that could be clogged up from someone running it with the wrong mix. You can usually take the muffler apart and either remove the screen to test or replace it.

[natemoen]

The consumer grade vs professional grade myth is true. I used to work at Grainger and talk with a lot of tool manufacturer reps and they say that it is true. They will admit that they don't expect (or want) consumers to attempt to fix them. They expect them to be used, abused, and then replaced.

[jjz28]

Iwas thinking the same thing on the spark arrester. I always take mine out. could have a bees nest in the muffler too to clog it. i Always adjust my hi- lo on mine to my likely.

[WMarshy]

TC, first lesson is never lend you machine to someone who's going to loan it out, things almost always get broken that way. Sorry for your loss.

As to your questions,

1. Fact, it is common (for newer saws) to have the recommended number of run hours listed on the saw for rebuild. I'm not sure when they started putting that on the saws but it is recommended to rebuild top ends on 2-strokes after 150-200 run hours. The same applies to dirtbikes and the more performance oriented they are the lower the number of hours are to next rebuild. I have never heard of the run hours in the model number, I think thats a myth.

2. True, your friend is right. Take a compression reading and let us know what it is. If its below 80-90 then your due for a new top end. It might run with 80-90 but it will be gutless and its only a matter of time before it eats itself.

I'm not that familiar with your exact model but if you can, take the exhaust+intake off and take a look at the piston and ring at the port. Take a flash light and shine it into the spark plug hole and turn it over slowly and look for scored piston and rings/cylinder walls. If you have low compression and some scoring on the piston/ring then its due for a rebuild. Their relatively simple machines and don't require much, they usually will dies from overuse (not rebulding them) or for not adding enough (or any) oil in the gas. Keeping a clean air filter on it is important.

Also, they are picky about the gas you put in them, I know my new saw said dont use gas that is older than 45 days and use high grade. These small engines are sensitive to ethanol so if your local gas station sells the high grade without ethanol like mine, then use that.

[DGXSER]

Not sure on the Poulan models, I have an OLD Stihl 024. It had to be made in the 70s just from the history I knwo of it. Belonged to a friend of mine when I bought it, he got it from his BIL who got it from his Dad (my friends FIL). Each had it for probably 5-6 years easily, and I have had it for probably 10-15 years. I recently had issues with mine running, put new gas in it with new oil, would not run. Ended up being the elctronic ignition on it.

If it losing power while trying to cut, make sure it has a good sharp blade and that the dude who borrowed it did not put the chain on backwards. you might be surprised at how many "pros" try to cut dirt with chainsaw and otherwise abuse equipment, it was never their own.

[jimbilton]

Small engine questions: Chain Saw type!

Also, check the fuel tank breather. If air can't get into the tank, fuel starvation is the result.

[soccer4m]

get another

Hi TC,,,,I have the same saw, great saw when they run, light and powerful,,,,,but when they go bad, I had one go bad also. I spent more time trying to figure it out why it ran like crxxp and bought another on amazon. They run 70.00 on Amazon, and are guaranteed. I bought the same saw again and its back to normal without the headaches.........good luck, Mike in Sun Diego

[xs11jack]

I think you aught to have a serious talk with the B-I-L. Tell him straight out that you are going to take the saw to a dealer and HE is going to PAY the bill!! It sounds like you let him walk all over you. No one should treat anyones equipment like that. Make him pay.
Ole Jack

[TopCatGr58]

Update!

Hey Jack,

Thanks, yeah I would like to regarding the B-I-L, but he actually LIVES with us, no job, no health insurance, busted KNEE, etc., no visible means of income!

Anyways, a further inspection of the saw first revealed a clear/clean spark arrestor screen so that was ruled out as a problem. Put a new spark plug in it, had never changed it! While at the local lawn/garden shop after discussing the saw's problems with the counter guys....the Service tech actually charges a CONSULTING FEE , and they suggested trying their fancy premixed high octane NO ETHANOL small engine fuel. Very pricey, but worth the try/experiment. I had mentioned removing the old large ceramic/stone filter and run it open; got a new one put in. Got it fired up and after several minutes of working with it, got it to actually keep running, and will actually IDLE now, so aside from the fuel filter and spark plug, looks like it may need better fuel than what I had been using.

Because it's a simple engine without electrical/component ignition and timing control...it probably DOES need the higher octane fuel vs. the weak low octane that our cars can use!!! Thanks again for the help and info.

T.C.

[WMarshy]

Its nice to hear its not a total loss. Like I said earlier, if you can buy non-ethanol gas at your local station then use that. Dont think you have to buy the premix gas from now on. The older saws are definitely less forgiving to ethanol. Just as important as the gas it the oil you use. If you buy quality oil made for chainsaws then it has fuel stabilizer in it and additives for the ethanol. Dont let your gas go stale either that can be just as bad.

Heres an interesting read on ethanol and chainsaws...

http://www.google.com/url?sa=t&sourc...lIn3_WDtTur-DQ