High needle all the way in still rich

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CoreyB

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Hey all, I know that this as had to been covered somewhere but I can not find an answer with the search. (Probable not asking the correct way.
I have an stihl 056 super that I recently got. It runs well but to get it lean enough to clean up on wood the high needle has to be all the way in. And even then it still burbbles a tiny bit.
Why would my needle have to be all the way in?
Will this cause long term problems?
How do I fix it.
Thank you in advance.
 
Just to make sure, you are turning the needle furthest from the engine, not closest? The needle closest to the throttle shaft is low speed and the choke end is high.
 
A couple other things, sometimes a lot of sawdust builds up between the diaphragm and cover plate, which can prevent it from functioning properly, or the metering lever is set too high, so the fuel pump pressurizes the fuel behind the diaphragm, at which point it'll find another way into the airstream. Also watch for the metering lever spring, if it's rotted it won't put the necessary pressure on the needle to close the valve, so the fuel pump again will pressurize the area under the diaphragm.
 
What carb is on it? That's perfectly normal for the late style WJ-4 Walbro, as it has a high bypass.

If it's a standard Tillotson HS-118, then probably a welch plug is loose or the metering lever is set too high.

Take it apart (if it's a Tillotson) and see if you can make the welch plug spin around with a sharp prick punch and using hand pressure only
 
Ok I am going to sound ignorant (because I am).
1. Air filter is clean
2. The L needle is out about 3/4 out vs 1 turn by the sticker.
3. How do I tell which carb it has?
4. Is there any diagram that will show where the rest of the suggested parts are? Like the Welch plug, metering rod, diaphragm, ect.
There also looks like there should be a needle closer theengine side. The high and low almost touch being so close together and on towards the engine is a hole looks the size for a needle.
Thank you all for helping me sort this out it is very important I have this in top running form
 
the diaphragm, metering needle, welch plug, etc are under the metal cap on the side which the H and L screws are.. I think on the 056 that's the 'top' side of the carb as it's mounted on the saw. That hole closer to the engine must be some optional thing which is probably a blind hole. I have an 056 Super with carb issues right now as well... but haven't had time to look at it closely.

Since this carb is mounted 'upside down' compared to how they usually are mounted, the fuel is above the venturi.. I think there's some sort of screen or check ball in the main jet that may be supposed to prevent fuel dribbling down without enough airflow.. something could be wrong with that too.

Welch plugs as little aluminum disks that are pressed in to a recess, they have a little bit of a 'dish' to them so they expand and stay put when you press them in
 
this will help
 

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What carb is on it? That's perfectly normal for the late style WJ-4 Walbro, as it has a high bypass.

If it's a standard Tillotson HS-118, then probably a welch plug is loose or the metering lever is set too high.

Take it apart (if it's a Tillotson) and see if you can make the welch plug spin around with a sharp prick punch and using hand pressure only
this could be it...I have a later model 056 mag II with a wj-4 and the little diagram on the side of the saw that tells you the carb settings says H-0 and L-1.
 
I looked at alone attached diagrams and can not say for certain either of those are the correct carb. Can someone identify it by the photos?


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Ok what is a welsh plug and where do I find it? I got the carb out and cleaned it some in gas but am at a loss on the Welsh plug
 
Go buy a rebuild kit for your carb and replace all gaskets. The stamped numbers you are looking for are on the other side of the carb. You'll need an 8mm socket to take the two carb nuts off. Remove the fuel line and throttle linkage and the carb pulls right off. Leave the fuel tank cap loose to it doesn't blow mix out of the fuel line. The Welch plugs are likely in place. They're the round aluminum discs under the diaphragm inside the carb. Since it is running it is likely you only need to replace the gaskets and nothing else.

Edit: I forgot to add that the first part of the lettering might be missing off the edge from stamp misalignment. It will start with "hs" if tillotson. Sometimes you'll just see the "s" or no letters at all.
 
Here's some pics of a wj4 off a 056mag. Removing it's easy. 2 8mm nuts and 2 little itty bitty Jesus clips hold the throttle and choke rods. There is no fuel line to remove...just an impulse line. The fuel enters the back of the carb here.
image.jpg


Im pointing to the bypass here...this is what hotshot was referring to and why you can close the high side...this must allow enough fuel to supply both the high and low side on these wj carbs.
image.jpg


This is the welch plug...if you have a tillotson this could be the reason it's still running rich with the needle closed...take the L needle out and spray brake clean in the passage gently...you'll see it leak around the plug if it does leak.
image.jpg


Lastly here's a pic of my 056mag...notice how they recommend 0 as the high speed carb setting...my saw has the walbro. I still leave it slightly cracked open...makes me nervous with it closed for some reason.
image.jpg


Edit: I see that backhoe lover beat me to recommending how to check the welch plug for leaks. Props.
 

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You can also check the main valve.
1. Take out the high needle while leaving in the low
2. Pull the metering cover and gaskets.
3. Get a small piece of fuel line and stick it in the high needle thread port
4. Put of finger over the brass piece and the small hole below it
5. take the piece of fuel line stick it in your mouth
6. You should be able to blow. you should not be able to suck back.

ok on the brass peice bypass . Take a small piece of 3/16 fuel line about 1 in long. make sure it is cut straight. put it over the bypass valve should be the same as the main valve. should let you blow. shouldnt let you suck back
 
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