stihl 021 chainsaw won't start, unless pulled 62 times daily for 6 days

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my chainsaw is _exceedingly_ hard to start, I'm near pulling my arms right out of their dern sockets...
saw has excellent compression. also has _brand new bosch spark plug, correct plug # correctly gapped, & plug is "known to be firing" (removed plug, ran ground wire to muffler, watched and pulled), carb is freshly rebuilt, fuel pickup clean as a whistle, fuel is one day old, of the correct octane and oil-mix, using 2 stroke good oil. saw gets gas, as proven by 'gas smell' and look at plug removed during my numerous "pull-fests". saw won't even fire a LICK usually, meaning 99.99999 percent of the time, even if I use ether. not even a quick, weak 'pop pop'....
in desperation, I even built a crude 'pre-heat' chamber for the saw out of old plywood, ran a small electric room heater into one end for a half hour - "heat-soaked" the entire saw up to a hundred degrees, which didn't even help. air cleaner clean as a whistle. the 'one turn' carb adjusting screw IS correctly at its 'one turn' setting, and the other one, is at, well, wherever it was? (moving it seems to change the saw from 'super-hard starting' to 'super-hard starting' and back ;-)
the stihl owners manual is 'very foggy' on how to set the carb adjusting screws, especially in relation to each other (but his seems to matter). when I _did_ finally get it running yesterday, after its' traditional sixteen million arm-wrenching pulls, it ran kinda lousy - had to keep 'revving it' between cuts...wouldn't idle, even after being warmed up and making some cuts...
what to do next? anybody care to suggest an 'initial setting' the 'low speed' screw should be at? and why does moving THAT screw seem to make adjusting the other one imperative? near as I can determine, it's only a "throttle stop" of sorts (it keeps the throttle plate from closing 'dead shut' completely).
ps-the blade stays in motion, but 'weakly', between cuts (I couldn't care LESS about that at this point, though). when I 'rest the blade' on a log, when it's 'near idle', the blade stops...so, big deal! I just wanna be able to make CUTS-I don't care if the blades in motion between cuts or NOT, at this point...
um, what controls the timing on these saws? I'm guessing it's 'fixed' (or is it?). the sparks the plug made during it's 'removed visual' test were tiny, blue, or blue-white...
grateful for any troubleshooting tips & ideas/thanks :-)
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Check your fuel lines for cracks. It may be that you have everything else correct, but you're sucking more air than fuel, despite your adjustments. That would fit with the "had to keep 'revving it' between cuts...wouldn't idle, even after being warmed up and making some cuts".
It happened to me (& I couldn't figger it out either <g>).
Joe F.
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In article

I have a weed wacker with a similiar problem, so I tried squirting some mix directly into the carb intake to verify it was a fuel problem. It started immediately and ran fine. Being lazy and not overly competent in rebuilding small engine carbs I just squirt a bit of mix in when I want to start it cold. Once warm it restarts easy. If it sits for an hour It needs another small squirt. Crude, but effective.
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On 22 Jan 2004 09:11:49 -0800, snipped-for-privacy@aol.com (bill yohler) wrote:

One thing you can check is the amount of spark. Is it visible in sunlight? Or can you hold the plug a little away from the engine and see a spark jumping from the electrode to the engine? And if just the plug wire is held close to the engine is the spark better than the one that jumps from the plug? I have had brand new plugs that were bad. And magnetos have more spark when spinning faster so maybe that's why the engine runs better fast. I have also had magnetos give weak spark because there was moisture inside. The fix was to let them soak in a 250 degree oven for an hour or so and then turning off the oven and letting the mag cool in the oven. If I grab the plug wire and turn the engine over slowly and don't get a pretty good jolt I suspect the points, mag, condenser, or any combination of those. I dunno how old your saw is so it may or may not have points. Good Luck.
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    Be SURE the choke is closing properly.
    Mixture screws out 1 1/4 turns is a good place to start
    Even brand new plugs can be bad, if you have another on hand try it. Even if the one you have sparks in air. It's a different story under compression.
    Check fuel lines for cracks or airleaks.
    Check the pulse source for the diaphragm for a blockage or disconnection. This is the connection between the carb and the crankcase pressure that make the fuel 'pump' in the carb work. Sometimes it looks like a fuel line, sometimes it's a orifice on the engine side of the carb, matching a similar hole in the carb manifold. Not sure about the 021.
    Make sure the diaphragm is in good shape. (pliable, no holes, not completely stretched out)
    Clean the carb again. Get a carb kit. Disassemble it COMPLETELY, clean it with real solvent, blow out all orfices with compressed air. Reasssemble according to a parts diagram. Lots of carbs get reassembled wrong.
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Peter Snell wrote:

And make sure that you don't/didn't use RTV as a sealant on that carb.
I once drove a Datsun for 40 miles at 20mph because I made that mistake.
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bill yohler wrote:

ONE TURN SETTING??? are you talking about the idle needle?? if so on just about every small engine i saw it say you tighten it to bottom it out (no hard, just about hand tight with a screwdriver) and then open it one and one half turns out and then when running you adjust it finely by a small amount.. maybe this is why it is not starting???? and you say the carb. is rebuilt?? who did that You?? if you know what you doing rebuilding carbs what are you asking questions here for??? not to be funny or in bad taste, but the carb might not be rebuilt correctly and that is why it is not starting.....
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If its fitted with a foam air cleaner that may need to be oiled properly. Seems a common problem on some lawn mowers that can make them difficult to start as they run too lean.
bill yohler wrote:

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bill yohler wrote:

Since it will run, it is not the spark or muffler . If it will not idle and is hard to start (also low rpm) then there is either an air leak or the idle circuit is plugged in the carb. I would check the gasket surface where the carb bolts on and the bolts are torqued properly. Disassemble the carb and blow out all internal passages and jets with compressed air. Wear safety glasses!!!
ff
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Is the check valve in the gas tank installed and working properly and there are no cracks in the hose? Someone correct me if I'm wrong but a defective filter/check valve won't hold the fuel in the line making getting the thing started a real chore.
I also agree with the poster who questioned the possibility that the carb may not be rebuilt to factory specs.
Jimbo

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Several things come to mind. Might be air leak going into the crankcase some where. Might also be the wrong air gap from the coil to the flywheel. Might also be a points model saw with old points. Might be carb setting (though, I doubt this, after all this cranking, and trying ether).
Your clue was the "tiny blue sparks". If memory serves, the point gap sets the timing.
Sure sounds more and more like trouble with points (My Homelite is set .015 point gap). Or more likely an excessive gap from the flywheel to the coil. Iusually set the flywheel gap by tearing the end off aspark plug box, put it between the coil and the flywheel and tighten it up as bes tI can. And then rotate the flywheel to get the cardboard out of there.
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Well Stormin, your memory isnt doing to good, the points gap has nothing to do with timing, points gap is Dwel.
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Should have bought a Poulan!
Visit my website: http://www.frugalmachinist.com Opinions expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy.
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Lol, Poulan for pulling?
Roy wrote:

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Yep, I agree. Then you could get your exercise jerking on that sucker instead of the one you now own. I have a Poulan and that's where I get my workouts. <g>
Harold
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On Fri, 23 Jan 2004 13:24:52 -0800, "Harold & Susan Vordos"
......and in reply I say!:
I said it before and I say it again
"You have to poulan poulan pull...."
Funny thing is, the one I had went for 10 years,. It was a little 14" job, maybe 30cc? I put a tungsten tipped chain on it, and cut dry jarrah (hard brown stuff) logs up to 20" + for years, and the thing, once it started, just kept going. I never looked after it, because it was always a pest to start and get to idle, from the get go, and I wanted it to die die die! But it did not
In the end I threw it away (yes, literally...at least twice) and went and bought a Husky....which is not as powerful, but does start on the third pull at the end of every summer.

**************************************************** sorry remove ns from my header address to reply via email
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snipped-for-privacy@iinet.net.au says...

Hi Nick,
I use Poulan saws for trimming branches after I drop one. I use Husqvarna's for felling, and I use a Stihl for bucking. Different chain profiles on every saw. I do this for a living. Of course, these saws and their chain profiles are personal preferences. I only cut in the winter when the trees are light, so I use a gas stabiliser during the off season.
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Since you stated that the carb was rebuilt - my question is if you took the carb off and gave it to someone or did you hand them the entire saw.... the gasket on a lot of smaller carbs (between the carb and the cylinder) has a very small hole for vacuum to operate the fuel pump in the carb. If the gasket is not positioned perfectly, the hole gets "covered up", and also can "swell almost shut" so I would check the tiny hole first - check fuel lines for cracks, deterioration, etc. Muffler screen clean? The carb may have been assembled wrong, especially when it comes to the fuel pump diaphragm as they are usually assembled with a separate gasket, some have the diaphragm on TOP of the gasket, some UNDER, and this makes a difference on how far open the needle valve gets moved. The points - if you have them - on a lot of Stihl saws are opened and closed by a cam mounted on the underside of the flywheel - I don't recommend you pull the flywheel unless you HAVE the special setting cam ring (Stihl) for setting the point gap. I have worked on enough Stihls that I now REFUSE to accept them for repairs - I talked to Stihl once about a saw and their quote was "We don't support anything over 10 years old... no parts, no literature, no pictures, no part numbers, no technical support. If it's over 10 years old, throw it away." That's when I quit working on Stihls. Ken.
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(Ken Sterling) wrote in message

What does the plug look like?? Wet??? what color? This will tell you what is wrong....
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On 22 Jan 2004 09:11:49 -0800, snipped-for-privacy@aol.com (bill yohler) wrote:

I've owned a Stihl for over 20 years and it has been very reliable and easy to start. However, the other day I tried starting it and it refused to even fire once. I must've pulled that starter rope a hundred times.
But, it had been over two years since I had last used it. I figured something had gotten gummed up and/or stuck during the layup. But, I wasn't about to take it apart with all the dirt and crud on it.
The first thing to do, then, was to blow out all the accumulated crap, especially all the gunk on the air filter.
After the air treatment, I gave the rope a pull and it started right away.
I figure that blowing it out really good must've unstuck whatever was causing the problem. After that, the engine was as reliable a starter as it always has been.
Orrin
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