Stalling out Ryobi, weed trimmer, model RY34440 question

[Big Bubba]

Hello everyone,
I have another question for all of you. Yeap, I am helping my dad do all the carb problems on his lawn equipment business he just started. He thinks I do good on carbs so that is waht I do for hime plus I make a little money at it. OK enough about that for the real question. I am working on a Ryobi, 4 cycle, model RY34440, weed/gas trimmer and I have had the carb off that thing two times trying to clean it out with carb spray and blow it out with compressed air. Anyway, it will run when the choke is on but not that good but when I come off the choke it boggs and dies on me. I have removed both the Low speed and High speed adjustment screws and yes I marked one for Low speed so I know which screw is which before I installed it. But I removed those 2 scews and sprayed carb cleaner in both and blew out with compressed air. I did this on the entire carb with the gaskets removed and the needle and lever removed and cleaned out the little screen. I also replaced both fuel lines with the new Oregon Yellow colored ones and put the filter back on correctly and installed the fuel line with the filter on it on the primer bulb nipple and the other one on the farthest away nipple. Anyway, I am at my wits end with this one trying to figure out what else to do. I did happen to not rip the gasket but pulled a little bit of it apart like a layer of the gasket that goes between the carb and the plastic intake I guess that is what it is called when taking the carb off to clean it inside. Also I was thinking about, maybe, soaking the main metal part only of the carb in the gallon jug of Gunk Carb and parts cleaner for one day and trying it again and purchase a brand new gasket that I was talking about that might be slightly damaged causing an air leak and it only running on choke. What do you guys think. I have not adjusted the valves on it yet but was thinking about doing that also. It says to gap the valves at .005 for both intake and exhaust so I was going to do that also. So I need help or good suggestion where to go next on this one. I feel like a failure but those weed-eater carbs are kinda my week point. I guess because there so small and have a few more gaskets. One more thing I have set the low speed and high speed adjustment screw at 1 and a half turn out from lightly seated when I crank it up and still having the issues. So this is where I am at with it.

 

[Grub54891]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Well I'd look for an air leak,at the intake after the carb,or fuel lines will get micro cracks in em and suck in air.she is running lean for a reason.Lines inside the fuel tank also. Good luck!
Grub

 

[Limited-Time]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Remove the muffler and clean the spark arrester screen. Many times these clog up and keep the engine from breathing correctly. Like a clogged catalytic converter on a car.

 

[CharlieB]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Dies when you turn off the Choke, still too lean on the idle circuit, switched the idle/main needles, or idle circuit still has crud in it.

Do NOT soak the carb for more than an hour if your chemical is any good, it will remove the factory anodized finish, inside and out, the alcohol/water in the fuel will accelerate corrosion inside all fuel wetted surfaces.

Tear down the carb, with safety glasses ON spray chemical in each needle hole while looking down the carb throat. You should be able to see where the fuel/spray comes out and determine which is the idle and main passages. This will verify you have the needles in the correct hole. This will also confirm the idle passage is clear.

Once reassembled and sure the idle needle is in correctly if the motor still dies without the choke, add more idle fuel.

 

[Levinz11]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Remove the muffler and clean the spark arrester screen. Many times these clog up and keep the engine from breathing correctly. Like a clogged catalytic converter on a car.

I second this. My Echo even has some kind of pseudo cat on it and it clogs annually. Good luck.

 

[Ironrogue]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Ditto on the spark arrestor screen...just remove it and be careful not to start a fire!!

 

[gm280]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Not exactly sure which carb you are working on (Walbro or Zama) but some of those carbs have plastic/rubber check valves in them so soaking the carb may distroy those little valves...just saying. If you look real close under the needle/seat lever area you will see a one way check valve there with most likely a brass top. Just letting you know...

 

[mscher]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

I have and older Ryboi 874r with the Walbro carb/fuel pump.

I can usually count on a complete micro-surgury dissassembly of the carb every spring, to clean out what amount to a tiny grain of sand, which is some ethanol crud, that would not come out otherwise. I do drain the gas and run it dry, each fall.

Also,the trimmer need to have the foam air filter both clean and oiled, for the proper air flow, as not not effect the air fuel mixture.

"The condition of the air filter is important to the
operation of the unit. A dirty air filter will restrict air flow
and change the air/fuel mixture. This is often mistaken
for an out of adjustment carburetor. Check the condition
of the air filter before adjusting the idle speed screw."

 

[dolluper]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

intake leak,lean condition,over rich to compensate,runs good with choke on or close to on

 

[Big Bubba]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Yeap, I have been busy helping my dad clean/rebuild riding lawn mower carbs like Walboro, Nikki, and Tecumseh 7 series carb. Anyway, I will check out the spark arrestor screen by the muffler and the intake gasket after the carb intake. My dads friend has a Weedeater, Feather light doing the exact same thing and wants me to work/clean/adjust the carbs. So I think I need someone to give me some pointers on how to clean these small carbs out. I seem to be weak on figuring out what is wrong with them and what to really do to get these things running again. My dad gave me about 7 combination of blowers and weedeaters to work on but I hope someone can give me some good pointers or instructions or a good video on how to clean these out correctly. That is what I think will help me out becuase, like I said I am weak in working these tiny carbs out.

 

[CharlieB]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Idle passages are soo small it doesn't take much to restrict flow.

Biggest problem with most is the alky in the fuel stiffens the fuel pump diaphram, they cannot pump enough fuel for full throttle/load.

They might start and run from idle to just off idle, then bog and die from lack of fuel.

A local lawn mower shop stocks most of the Walbro and Zema kits, and I often buy 3 or 4 at a time as all the neighbors bring me theirs every year or two and I constantly find the diaphragm hardened.

 

[gm280]

Re: Stalling out Ryobi, weed trimmer, model RY34440 question

Idle passages are soo small it doesn't take much to restrict flow.

Biggest problem with most is the alky in the fuel stiffens the fuel pump diaphram, they cannot pump enough fuel for full throttle/load.

They might start and run from idle to just off idle, then bog and die from lack of fuel.

A local lawn mower shop stocks most of the Walbro and Zema kits, and I often buy 3 or 4 at a time as all the neighbors bring me theirs every year or two and I constantly find the diaphragm hardened.

You are absolutely 100% correct about the hardening of the diaphams in those little carbs. The only thing that will make them work properly again is a new diaphragm. And you can buy the entire carb rebuild kits OR the GND (Gasket N Diaphragm) only kits which are a little cheaper. But I had two carbs this season with hardened diaphams in them and while they did crank up, they both bogged every time I tried to throddle them up... New diaphams solved the problems in both...