I am having an ongoing problem with 021 carb.I purchased saw off TM I took carb to pieces and installed new valve diaphragm . And cleane and blew. Then saw started and I used7 tanks gas and then too much fuel getting through. So took carb apart and blew cleaned etc and reinstalled. And yes another 5 tanks but during this period , often wouldn't start and plug wet . So today I refueled and noticed after lots pulling and indeed motor did start that while the motor was 'just' running spluttering , there was visible fuel droplets spraying out from the open choke butterfly . So obviously too much fuel. Is this because the fuel needle valve isn't shut because ! Or is the pulse diaphragm has hole or ! Thanks for assistance My 046 starts within 5 pulls and then first pull ever time so I know stihls can do it Is a new carb the solution! Or a new full kit!
mechnificent,
Nov 2, 7:00pm
Spitting out the carb is common, might not mean anything. Have you checked the fuel tank breather! Are you sure the "float" needle is seating right, not dirty! And I suppose you have tried experimenting with both mixture screws! It might be running too rich on the idle to overcome a main jet leanness.
I always set the main so it runs right at full throttle, just a tiny bit on the rich side of maximum revs. Then I adjust the idle mixture and speed. I get the idle mixture right so there is no flat spot, which is quite often a tiny bit richer than the best mixture, then I adjust the speed to keep it idling.
mechnificent,
Nov 2, 7:05pm
If all those things are ok, might be worth looking at the exhaust, the outlets from the cylinder could be partly blocked, not common on a stihl but you can never tell, or there could be a half blocked muffler, some have a gause on the outlet. Another thing that can cause those symptoms is a distorted bore, letting the compression blowby into the sump. not so common either, but it can happen and lead to hard starting even when they have good compression. The best test for that is to strip it, get a ing and put it in the cylinder, then keep looking down the sides of the ring as you hold it up to a bright light, and slowly move the ring down the bore. Sometimes they are only distorted down near the bypass ports, and above it can be ok.
les37,
Nov 2, 7:34pm
to much fuel, check fuel filter in tank has not fallen off,it becomes restrictive as it gets older , leaning the mixture out, and mixture screws get adjusted to suit this, if its fallen off it will run rich.
snoopy221,
Nov 2, 7:36pm
With what you have posted i'd be more inclined to check the coil air gap and clean the coil faces and the flywheel face. A little bit of rust and a tired coil(021's are known for that) will wet ya sparkler and she won't fire up ya juice. What i read between the lines is saw starts cold-use it for a few tanks and coil is hot and tired.
mechnificent,
Nov 2, 7:57pm
With most makes of chainsaw, the smaller models are prone to heat build up when you keep using them for more than one tank full. Sometime just letting them sit for a quarter of an hour between tank fills will let them cool off and they can be used all day. Try and fill and use them one tank after another, and they get hotter and hotter and then the mixture needs adjusting and they get unreliable.
The bigger models don't seem to suffer from the heat build up of smaller models.
snoopy221,
Nov 2, 8:03pm
Try and fill and use them one tank after another
Biggest thing there is when you fill and screw the tank cap on-start the saw. Don't walk away and leave the saw for 5 minutes on a hot day-or it WILL flood. [And when you go through 5 or more litres of fuel in a day in the same saw well.ya know these things.]
mechnificent,
Nov 2, 8:08pm
Yeah I agree with that too Snoopy, if they are all tuned right, and going ok, better to keep them going, or let them sit for that quarter hour I was saying.
The little ones don't like being worked all day though. seen it time after time. If you want to work all day, get a big one. they start and idle steadily for minutes at a time if you are milling, and they don't wear out.
snoopy221,
Nov 2, 8:09pm
Personaly i'll throw this one in ere. Me being the houer i am-gimme a flooded saw like that-and i'll put the chain brake on and drop start it on full throttle. [Now we know ya can't drop start a saw-OSH- and all-but when a working chain brake is on-and used by the operator-why not!]
snoopy221,
Nov 2, 8:11pm
milling with a 40 cc 021. mmkay.
mechnificent,
Nov 2, 8:15pm
No Snoopy, I was saying that you need a big one if you want to mill. The little ones get temperamental after a tank or two. the bigger models will start first time, sit and idle, run sweet all day. little ones are made for doing lighter work, and less of it.
jmma,
Nov 2, 8:17pm
Much better without chainbrake , can't rev with that damn thing on (o:
snoopy221,
Nov 2, 8:23pm
Most milling is 30 inch bar + and being ripping it needs a good 80cc + saw I M O
Little saws have their uses.big saws do NOT like little branches. 084 does the mill jobs.but an 025 will run all day long sweet as limbing
[Personaly i've never been a fan of the MS style clamshell 021 with only one crank web.prefer the 025 with 2 crank webs]
The tank vent will be in the air filter housing won't it!
snoopy221,
Nov 2, 10:52pm
Meh the tank breather is the special threaded screw in the end of the plastic tube to the left of the air cleaner. Never Ever seen one of em fail on a still
jason18,
Nov 2, 11:53pm
HOLY SHIT SNOOP I can read and understand that!
fiddle44,
Nov 4, 4:10am
saw needs a new carby kit thats all,any hassles let me know
beart0y,
Nov 5, 9:16pm
Have you done a pressure/vacuum test! Crank seals may be leaking.
domaine,
Nov 7, 1:15am
Hi, yes thanks for all input. I removed carb again today and took out inlet valve blew some air and put it all back but tried to get a little more spring tension. Then saw started , adjusted jets and goes ok until next time. The attack breather is a tube running up to some weird valve like assembly located by screw jets. Breather seems to allow air to enter tank but not blow back. Is that right. When I log , I use big saws 066 and 46 to fell and like a little saw to limb but it MUST start every time like my 66and 46 always start every time. I'm not confident that the 021 will . I possibly end up buying a new 52. Ccchineses saw. Or a new. Stihl 026 Thanks for your time
mrfxit,
Nov 7, 1:08pm
It sounds a bit like it needs a complete strip down & a full gasket/seal rekit. It's a full day job (in between other stuff) but would be well worth it. Including checking for joining surface defects when stripping
Would very likely take less time with better results then all the current mucking about
domaine,
Nov 7, 10:55pm
Yes to be sure.Today 3 tanks and I rate the saw on if it floods or not and if I have to use choke to start , means motor and carb ok. I'm guessing a tank vent, or intake valve or intake valve diaphragmwhich works ok until little bit speck or. Gets under valve. But thanks for input.It is a throw away saw compared to my other stihls
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