# ST-224 3 years old low idle and surging



## linuxos77

Only on my third season on a Husqvarna ST-224 (from Lowes). The engine is running VERY rough, pull starts right away full choke, I let it run for a bit to warm up, soon as I remove chock engine idle goes up and down but never reaches full idle. It started doing this late last season but I limped it along figuring I'll get to it this fall. Well here in New England we got a quick 6 inches of heavy wet snow last night so I had to limp it again. The surging seems to lessen under load, but it's really bogged down, much more than normal. I also noted this morning under no load (no auger) once or twice the engine did a small backfire (or pop anyway from exhaust). Last season I ran fresh gas, last tank I added Stabil and ran it almost out. Last evening I tried the lazy mans fix, poured Liquid Mechanic into the empty gas tank, primed and pull started a few times and let it sit overnight. This morning I added fresh gas and it fired right up but is running in the poopr condition explained. Any ideas of things I can/should try? I'm thinking carb needs to be cleaned? Does this engine/model have mixing screws or other adjustments that may be off and need to be changed? Thanks in advance.


----------



## UNDERTAKER

linuxos77 said:


> Only on my third season on a Husqvarna ST-224 (from Lowes). The engine is running VERY rough, pull starts right away full choke, I let it run for a bit to warm up, soon as I remove chock engine idle goes up and down but never reaches full idle. It started doing this late last season but I limped it along figuring I'll get to it this fall. Well here in New England we got a quick 6 inches of heavy wet snow last night so I had to limp it again. The surging seems to lessen under load, but it's really bogged down, much more than normal. I also noted this morning under no load (no auger) once or twice the engine did a small backfire (or pop anyway from exhaust). Last season I ran fresh gas, last tank I added Stabil and ran it almost out. Last evening I tried the lazy mans fix, poured Liquid Mechanic into the empty gas tank, primed and pull started a few times and let it sit overnight. This morning I added fresh gas and it fired right up but is running in the poopr condition explained. Any ideas of things I can/should try? I'm thinking carb needs to be cleaned? Does this engine/model have mixing screws or other adjustments that may be off and need to be changed? Thanks in advance.


* The carb needs a ZESTFULL Cleaning. ALOHA From The Paradise City. :smiley-rpg027::smiley-rpg027::smiley-rpg027::smiley-rpg027::smiley-rpg027:*


----------



## JLawrence08648

Carb needs to be disassembled and cleaned. Spraying a carb cleaner in the holes works great on most carbs allowing time to dissolve residues, preferable using a welders tip cleaner in the holes followed with carb cleaner again. If no success then Berryman's carb dunk solution, letting it sit for 4 hours. Again, if no success, ultrasonic cleaner or new carb but I doubt if you have to go that avenue. Make sure you don't have a intake manifold leak or a leak in the primer hose.

Drain the gas and the carb, putting in a plastic bottle to check if there is any water in the gas and checking for clarity.


----------



## Kiss4aFrog

:welcome: to SBF linuxos77

Best thing to do is take it apart and clean it. If you're lazy you could try adding a measured amount of fuel system cleaner to it and let it run at idle a while and near full throttle a while to see if pulling the cleaner through the fuel circuits in the carb cleans out the gunk. 
I did this with a an old beat up rider I bought four five years ago that was hard to start, wouldn't ideal and ran fair. I ran a couple tankfuls of treated gas through it and I've yet to need to pull the carb. Starts easy, idles smooth without dying and good power. I like to use Lucas Fuel Cleaner.

.


----------



## JLawrence08648

I also use Lucas but for maintenance, for problems I use Seafoam, also use Berryman's.


----------



## GeekOnTheHill

The first and easiest thing I'd try would be to shut off the fuel valve and let the machine run until it runs out of gas. Then I'd add a quality fuel system cleaner (Seafoam, Lucas, etc.) to the fuel using the highest concentration on the product's label if one is specified (usually the "initial" dose rather than the "maintenance" dose), run the machine for about 10 minutes, and let it sit overnight. Then try it again the next day.

If the fuel in the tank were old, I'd drain it and use new fuel from a high-volume gas station, plus the fuel-system cleaner, for the above. If at all possible, I'd use ethanol-free fuel. But one way or the other, it would be fresh.

It's frankly a crap shoot whether it will work. Most carburetor-related problems are best solved by removing and manually cleaning the carb. But the mechanic-in-a-can approach costs little and _may_ solve the problem. Or not. It's worth a try in any case.

Richard


----------



## linuxos77

Okay so this weekend I removed the carb bowl, it was perfectly clean, no residue or anything. I then pulled the float and heavily sprayed in the holes. I also sprayed the pin and spring on the float. The plastic float moves freely and was not full of gas or anything. I put everything back together and it's still running rough. I broke it down a second time and did the same, and still running bad, how long should I let it run, should any improvement come on fairly quickly? The gas in the blower is new from high volume station and oil level is fine. Anything else to try? I'm thinking physically removing the entire carb might be beyond what this YouTube level novice can follow. Much more than removing bowl/float I might refer to calling a place to repair.


----------



## vinnycom

your motor is running too lean, the motor wants/needs more gas but carb cant feed it fast enough or you might have an air intake leak.
adjust mixture screws if equipped.

depending on why carb is not performing sometimes just spraying cleaner internally or using products like seafoam might "fix" the problem. if not then a further detailed cleaning is required.

mainjet removal, float and needle valve removal, mixture screws removal, if any, cleaning of said items and using a cleaner into every orfice, holes carb has and using a thin wire to make sure orfices are clear of debris and using compressed air into all orfices. using a ultrasonic cleaner to further clean also helps.

if u have an air intake leak using brake/carb cleaner or propane can reveal itself if using these around the intake pipe and gaskets to see if rpms change as motor is running.

how far you are willing to take it apart and clean the carb will determine how well the carb will perform. or just buy a new oem, aftermarket or clone carb.


----------



## dr bob

The jets are in a stcak up the middle of the float area. Even a tiny bit of crud will partially obstruct them, so getting the out and clean is essential. Remove the float bowl and the float, keeping track of the needle valve and the float pivot. Then a small screwdriver to unscrew the jets and remove them. A little compressed air will help clear any crud/debris from them, Deposits like residue fro old fuel will come out with a spritz of spray carburetor cleaner. Stubborn may need a little more action, but be aware that these are brass (soft) and are precision holes, so don't get aggressive with drill bits or stiff wire that's bigger than the hole is supposed to be. You should be able to see clearly through the hole. Once cleaned, reassemble and install the carb again. Because the problem showed up last year before storage, my nickel is on crud in the gas vs deposits during storage.

Before you turn the fuel back on, look in the tank and see if there's anything in there besides fuel. No rust, right? I still like to flow fuel through the line to the carburetor to make sure no crud is in there. After all that, fresh fuel with a suitable dose of fuel treatment/stabilizer is a Good Idea. I just treat the fuel in the can when I fill it. That way the carburetor never sees untreated fuel. I still run the carburetor dry after each use as the manual suggests for untreated fuel, just to be sure.


----------



## JLawrence08648

vinnycom said:


> depending on why carb is not performing sometimes just spraying cleaner internally or using products like seafoam might "fix" the problem. if not then a further detailed cleaning is required.
> 
> mainjet removal, float and needle valve removal, mixture screws removal, if any, cleaning of said items and using a cleaner into every orfice, holes carb has and using a thin wire to make sure orfices are clear of debris and using compressed air into all orfices. using a ultrasonic cleaner to further clean also helps.
> 
> how far you are willing to take it apart and clean the carb will determine how well the carb will perform. or just buy a new oem, aftermarket or clone carb.


I agree completely ESPECIALLY the last paragraph regarding the effort, the quality of this work, and how far are you willing to take it apart and clean the carburetor.


----------



## rclark04

Just an FYI more than anything. I have an ST 224, 2015 model, and it was surging. I thought I just needed to adjust the carb but you can hardly see the carb much less than adjust it. So I started disassembly and got to the carb, found there were no adjustments to be had, only the idle. I removed the carb, disassembled it, used carb cleaner, blew it all out. There are youtube videos that show this. Put it all back together and it runs great now. For some reason, on this particular carburetor they decided to put fixed jets so there are no adjustments. If you have a rough running or surging engine, looks like the only way to fix it is clean the carb. They do suggest after each use, close the fuel valve and run it till it stops. After the season for storage do the same then empty the carburetor bowl of fuel. I hope this helps someone maybe save some time and frustration.


----------



## tadawson

The reason for fix jets is the EPA and law, but even on carbs with adjustable jets, the only way to *correctly* fix surging is still to clean the carb . . .


----------



## Midskier

After get the carb cleaned / running issue resolved I suggest adding seafoam to your fuel can and use premium fuel, anything older than 30 days old pour into your card tank......never any trouble from my mowers or blowers doing this (or cars). Good Luck


----------

