Question about Husqvarna Chain Saw 20" Bar

1 Answer

Adjusting carb on husqvarna chain saw

The H & L needle valves on my husqvarna 51 chainsw need to be out several turns to get it to run. it than runs fine until you try to cut with it and than it bogs down. Everything i have read indicated the needle valves only need to be turned out 1 or 2 turns. Problem?

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 211 Answers

Hi First turn them(H and L) clock wise until the end and then adjust.

high speed H=3/4 turn

lowspeed L=1 1/4 turn

idle speed T adjust accordingly

best regards savumihai71

Posted on Jan 19, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya Repairman can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US.
click here to Talk to a Repairman (only for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Husqvarna 51 file size

Several bar and chain combinations fit the 51 model saw. If your saw runs an H46 / H80 or H81 style chain you will need a 7/32" (5.5 mm)
If you are running a H21 style chain you will need 3/16" (4.8mm)

May 02, 2014 | Husqvarna Chain Saw Models 51, 55

1 Answer

I have a Husqvarna 125 blower. Where do you start adjusting the high/low needle valves. Do you run them in and then do the 2,5/2 turns you mentioned. They are not set from the factory. Had trash in the...

2 needle adjusters? one should be marked L & the other H.I hope you removed them for cleaning. Re-install them turn to the right until they stop.Then back them out [ counter clock wise] 1 & 1/2 turns is a good guess to start from. try to start,you will need some patience for this as it is trial & error.Keep tweaking them until it runs. once you get it running the one marked L is low speed or Idle H is the high speed. Tweak them while its running for best performance. I just went through this yesterday with a john deere 2 stroke and ended up at about 1 turn out from full stop on the needle adjustments. I also did this with the air filter off so I could see when flooding was happening. When it did I had some compressed air to blast the excess fuel away. good luck

Oct 04, 2013 | Husqvarna Garden

1 Answer

My husqvarna 350 chainsaw starts but wont stay running for more than a few seconds


Find the gas/air adjustment screws on the carb (next to the the throttle cam where the throttle cable attaches. Turn the screws in all the way... GENTLY... Those are needle valves, and too much torque on them will damage the needle valve seats. turn both of them out one and a quarter to one and a half turns. Start the saw, and adjust one or the other screw in or out until the saw runs properly. If there is a plastic stop installed on the screws, remove it first, and replace it after the saw is running properly. You have to be patient while tuning the carb as it may take a while. If you adjust too much and the saw refuses to start at all, start over with the 1-1/4 to 1-1/2 turns out on the screws.

Aug 19, 2012 | Husqvarna Garden

1 Answer

Husqvarna 340 will not idle

To set the H and L adjustments, screw them in until they lightly seat. Then back both out 1 1/2 turns. This will get you in the ballpark. They will still need to be fine tuned for proper settings.

Apr 03, 2017 | Husqvarna Garden

1 Answer

Need to know what the setting is for needle valve on a 460. I increased the gap when I was trying to fix a problem of running too lean. Fix the problem, but messed up the needle valve. The problem was the...

Turn both H and L jet needles CW to stops (lightly), then back out 1-1/2 turns each CCW. This is a basic setting and will be rich. Start the engine and allow to warm up. Pull the throttle full on and turn the H needle CW until the engine starts to speed up, but continues to 4-stroke. Final adjustment is when the engine 4-strokes at speed with no load, but immediately 2-strokes when cutting. Release the throttle and allow to idle. Turn the L jet needle CW until the engine idles fairly well, but still allows the engine to 'follow the throttle'. Idle speed screw should be adjusted to keep the engine idling, but the chain should not try to turn. Hope this helps!

Dec 15, 2010 | Husqvarna Chain Saw 20" Bar

1 Answer

The chain saw runs okay until i start to cut wood on higher revs then it cuts ouy

Does it run O.K. with high revs. with no load, but dies when you start to cut (load) ? If that is the case your carb. needs to be adjusted and that is difficult to put into words. Without knowing what make of carb you have because they can change from year to year, and also depends on the model. Without knowing make of carb I suggest you try to turn the L (low) and H (high) needles in (clockwise) until they are lightly seated so you don't damage the needle or seat. Now turn them both out (counterclockwise) one turn as a start. Start your saw to let it warm up now rev it up it should not hesitate or run rough while reving up. If it does turn low needle out 1/4 turn or more if needed until it does not hesitate. (turning any needle out will let in more gas turning in less gas) If you get this far good idling and reving up, now adjust high needle the same way. With high needle you can also try turning it in. keep on adjusting needles in or out in small increments until it runs right. If you cannot get it running right after all this, you probably need a carb overhaul, just a cleaning or carb kit if diaphrams are stiff or damaged. I hope this helps you. Please forgive grammar errors. Let me know how you made out.

Dec 01, 2010 | Husqvarna "Chain Saw - 16" Bar, 3 Hp

1 Answer

How many turns out is the High and Low screws suppose to be adjusted. Also how many turns out is the larger idle screw suppose to be.

Turn both jet screws CW to stops (lightly), then back out CCW 1-1/2 turns each. This is a basic setting which should allow the engine to start and run. Before adjusting anything, check the fuel filter, air filter and muffler for plugging. Start the engine and allow to warm up. Pull the throttle full on and adjust H needle CW until the engine begins to speed up, but still 4-stroking. Correct adjustment is when the engine 4-strokes running free, but immediately 2-strokes when cutting. Release the throttle and adjust L needle CW for better idle, yet allows the engine to 'follow the throttle'. Adjust idle speed so that the chain stops turning, but the engine continues to idle. Hope this helps!

Jul 11, 2010 | Husqvarna Chain Saw Handle Models 50 51...

3 Answers

Problem keeping engine running on Husqvarna 22HP VT riding mower

Take the fuel bowl off and clean it real good as well clean the fuel jet. It may be the bolt that holds the fuel bowl on. I am not sure. I use my air compressor to blow it out also get a real fine wire and put through the fine hole may help. It does not take very much dirt to make an engine not run right. I repair a lot that way that is not running properly.

Jun 06, 2017 | Husqvarna 22HP VTwin Hydrostatic 42" Cut...

1 Answer

Husqvarna z5426 running rich and fouling plugs

Sounds like a fouled needle seat, or the float bowl is failing.

Start with:

Pulling your Carb, and cleaning it out. COMPLETELY.
A ton of people think "a shot of carb cleaner, and a gasket kit" is a carb fix. It is NOT, and WILL NOT fix a carb, if the problem isn't gaskets, and shots of cleaner!

Meaning, if she is running too rich, then too much fuel (as you said), and fouling plugs, remember there are only a VERY few things in the carb anyway as it is.

1. Needle Seat
2. Fuel Float Bowl
3. Butterflies
4. Fuel Ports
5. Air Ports
6. Gaskets/Diaphragms.


Pull the carb (Carefully!) and tear it COMPLETELY down (Carefully!). Note where stuff went, take your time, be patient.

When you have everything but the butterfly plates out, run some Gum-Out through each and every port, after you made sure to pull the Float Bowl, and the Needle Valve (and remembered how they went back in there!). Take some compressed air, and follow through (CAREFULLY!) on each and every port. Clean the very TIP of the Needle Valve. Shake your plastic Float Bowl. Does it have liquid inside? She has a hole in her. REPLACE!

If not, then this exercise was cleaning crud/residue that is ALWAYS building up inside carbs in 2/4-stroke engines world wide, every day. NOW do a "carb gasket rebuild".

Note: Remember that sometimes, crud/junk is testy, and stubborn as a mule to get out. Double check any screens above/below your Needle Seat and Valve. Remember that Needle Valves come with solid tips, and some with rubber tips. Regardless, be careful, and clean thoroughly! A Needle Seat that isn't getting closed, is a Needle Valve that is letting WAY too much fuel in!

May 29, 2009 | Husqvarna Zero Turn Mower Z5426

2 Answers

Husqvarna 51 chainsaw will barely run, magnito and carberator ok

Probably need to re-adjust the carburetor jets. They are very small screws in the base of the carburetor. They will be labeled with an "H" and an "L" . Set the low speed first by turning it in slowly until the rpm drops slightly then start turning it outward untill the engine idles smoothly. At that point you can also adjust idle speed. Then you need to be careful here but you need to hold the throttle wide open at the same time adjusting the high speed jet. Turn it in until the rpm drops then slowly turn it out. The rpm will keep increasing. Once you get to a point where it is max'ed out then screw the jet back in one half a turn. Changes in altitude like using your chainsaw in town versus going to the mountains for firewood can sometimes make it necessary to adjust the fuel/air ratio.

Feb 18, 2009 | Husqvarna Husky 165

Not finding what you are looking for?
Husqvarna Chain Saw 20" Bar Logo

4,389 people viewed this question

Ask a Question

Usually answered in minutes!

Top Husqvarna Garden Experts

Phil Walker
Phil Walker

Level 3 Expert

608 Answers

Doctor PC
Doctor PC

Level 3 Expert

7733 Answers

Roland W VanLue
Roland W VanLue

Level 3 Expert

486 Answers

Are you a Husqvarna Garden Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides