572xp carburetor nozzle

[buckin-wood]

The saw was running insanely rich and dying when coming off throttle. I threw a rebuild kit at it but still not holding vacuum and sounds like the nozzle is leaking. I can't seem to find a part number for the nozzle anywhere, but did find a part number for the 562. Anyone know if they happen to be the same nozzle? I know the 562 and 572 carb body similar as they use the same diaphragm kit.

 

[buckin-wood]

found a part number on Zama's website...



I don't see it available for purchase anywhere. I reached out to Zama to see if they could get in touch with a retailer that could special order it. No word back yet.

 

[Poleman]

I’m thinking it’s the same Nozzle by the build specs.
When you pressurized the carb put it in water/fuel to see if you can see where it’s leaking at. You’ll know as you’ll be able to see bubbles coming out of the Venturi from it or any other spot on the carb.
Possibly not the carb at all…. I had one that drove me nuts and it turned out to be a leaking transfer cover… after investing in another carb. Sealed leak and all was fine with the original carb. The 5 series saws dump fuel like crazy when they have an air leak as it’s trying to compensate for it… it a good thing as it saves burning up a saw… but can be hard to diagnose. I just knew mine was the carb which it wasn’t.

 

[buckin-wood]

When I first started diagnosing the super rich condition I assumed I was going to find a leak, probably crank seal, and auto tune trying to compensate. However the saw holds pressure/vac just dandy. The carb holds pressure on the feed side, but will not hold any vacuum on the purge side.

looks like the nozzle part number for the 562 el44/46/48 is different than the 572 carb. suppose it would make sense the larger saw might need to flow more fuel. so far I've struck out with everyone I've contacted trying to get my hands on the nozzle. The fact Zama lists the nozzle part number and indicates inventory makes me think I just need to find the right person to special order it. The hunt continues.

 

[buckin-wood]

I had a spare 562 carb on the shelf. Punched the nozzle out of the 572 and 562. Both are 5x7mm. Atomizer looks the same, but the feed hole is larger on the 572 nozzle.


562 on left 572 on right






this is a dumb idea right?




chances I can get all the brass out and don't clog the atomizer? I held the nozzle upside down while reaming the hole out. I'm hoping most of the debris fell out. Tried flushing a bit with kroil then a few minutes in the sonic cleaner with the feed hole facing down. I figure it's worth a shot.

Assembled the carb and tested. Holds vac on the purge side no problem now. I'm hopeful this was the root of the problem

 

[huskihl]

To test the nozzle, it should hold pressure from the venturi side. Sounds like you might have it though

 

[buckin-wood]

To test the nozzle, it should hold pressure from the venturi side. Sounds like you might have it though

yes sir. popped the end in a bit of fuel line and checked before putting in the carb

 

[Gvsu141]

I had a spare 562 carb on the shelf. Punched the nozzle out of the 572 and 562. Both are 5x7mm. Atomizer looks the same, but the feed hole is larger on the 572 nozzle.

Do you know if this worked for you? Do you have an update on this that you could share by chance? I'm trying to source a new nozzle for mine without spending $200 on a new carb.

I have a 572xp that the identical issue. Stumbling/ dying off throttle, stalling at idle. Failed vac test on The Purge side. Knocked out the nozzle and verified the check valve is not holding.

 

[Gvsu141]

Update: @buckin-wood - I used your idea here on modifying a 562xp nozzle, and it worked great! I've ran a couple tanks through it now, and I can confidently say the issue is fixed. Bad nozzle was the culprit.

A bit more details for anyone else coming across this same issue, so we don't have to spend $200+ on a whole new carb.

Symptom: 572xp stumbling/dying off throttle, stalling at idle.
To test: Failed vac test on The Purge side carb line. Indicated leaky nozzle check valve, and verified once the nozzle was removed.

-572xp uses ZAMA main nozzle part #A00700714. (Husky part # 579235401). Out of stock everywhere, but Zama mentioned possibly could be back in stock mid 2026.
-562xp uses ZAMA main nozzle part #A007705 or #A007705A. (Husky part # 576414201) I ordered this for $4.85 + shipping from Mowpart: MOWPART A007705A Nozzle

I drilled out the 562xp nozzle using grease on the bit to collect shavings. The 562xp nozzle had a 1/32" (.8 mm) jet, while the 572xp had a 3/64" (1.2mm) jet. I didn't test the 562 nozzle before drilling, but that calculates to just over double the area of the jet opening. So if you had either a 1.2 mm or a 3/64" drill bit would work.

 

[buckin-wood]

nice! glad you had success! I never got a chance to test the fix, I decided to tear the saw down and give it a proper porting... but then it got put on the shelf as other projects piled up