Craftsman 23cc weedwacker only runs fully choked [Archive] - HobbyTalk

: Craftsman 23cc weedwacker only runs fully choked

05-03-2009, 04:16 PM
Hey everyone im new here. I have a little problem. I have a craftsman 23cc weedwacker my neighbor gave me, because he was moving. The only thing is that it needs some work. I have a gas/oil ratio of 40:1. The gas is 93 octane. Well I first prime it a few times, and with the choke on full, it starts and will idle, ill let it warm up and as soon as i move the choke to half it bogs/dies right out. I tried cleaning the carb, and that dosent seem to help. Im lost and thats why im here for a some help. if anyone knows what maybe wrong and/or how to go about fixing it, please let me know

thanks again, steve:thumbsup:

05-03-2009, 09:59 PM
did you change the carb gasket(s)? if not try that. When you say cleaned the carb what exactly do you mean (IE: took it apart, just took it off and sprayed it)?

05-04-2009, 01:42 AM
no i didn't change carb gaskets, i took the carb off and checked the diapram(sp). and cleaned it with carb cleaner.

05-04-2009, 11:08 PM
change the gaskets, I'm not familiar with this carb but the diaphragm should be in the center or maybe has more than one gasket in the carb? if so change them all (there may be something you can't see and its just a good idea), see if you can get a gasket kit for it might save you some money if they sell a kit for it. maybe someone here can look it up for you. other than that there should be a small screen in the carb to catch small debri, clean that and be careful not to crush it cause they are fragile. And if possible let the carb sit in carb cleaner. if that doesn't work i would see if someone here can get you the specs for the carb to adjust it, and if anything get a new carb.

05-05-2009, 12:59 AM
Most likely just needs a carb adjustment. Start at 1 3/4 turns out from fully closed and adjust from there. If you have to go more then 2 turns out, you have a carb problem.

05-05-2009, 01:47 AM
okay, would sears carry a carb kit to replace the gaskets and whatnot, and are these carbs tunable? Ill also try leaving the carb to sit in carb cleaner.

05-08-2009, 01:49 AM
Yes, Sears should have the parts. Just enter the model #. I'm thinking new gaskets/diaphram should do the trick and do as hankster suggested.

05-08-2009, 12:57 PM
well i went to my local sears and they said they don't carry them, so i ended up buying a new spark plug. I tried cleaning the carb and what not and it seems to run, but the only problem is when i run to "fully choked" and move it to half or no choke, the screws that hold the carb and air filter want to come loose. I think its because i misplaced the , i think it was some sort of washer that was there so after i tighten the the top intake screw,(the only the choke Handle pivots on), and now its hard to move and it causees the that screw to come loose over time.

05-11-2009, 01:28 AM
Did you try the sears website? I am thinking the carb needs a soaking in carb cleaner and some compressed air to blow any debris from the tiny passages. There is a tiny screen to remove also. Remove inlet needle, there is a tiny spring under the needle lever that likes to jump, so be careful.

05-15-2009, 07:05 AM
I've experienced the exact same problem with my own 40cc craftsman, the problem is almost definitely the carb gaskets. One of the gaskets (under the spring) acts as a fuel pump to supply fuel to the carb. When these gaskets get stiff they stop pumping effectively. I had previously thoroughly cleaned the carb (small pasages and all) and the problem remained. The new gaskets fixed the problem. My carb has no adjustment screws (CA model). I picked up the gaskets from my local lawn mower shop. They had a kit with many extras in it but sorting through it I found the right ones. Pay attention to gasket orientation and that sometimes the gaskets that appear to be one are actually two stacked on top of each other.

Hope this helps....

08-28-2009, 10:25 AM
Hello Folks, I have read above the problems with the carb, and choke settings in order for the engine to run ... 1/2 to full choke. This definately indicates a fuel system restriction, or weak fuel system delivery.
My question is ... Will compressed air blown thru the orficies where the needles are for fuel adjust ... High / low ports ... DUE THE TRICK ?
I don't know whether it has a fuel pump, a diaphram. The illustration for my MODEL 234.795410 doesn't show it. The gas tank is above the carb in the upright position. THANKS-TO-ALL, for your help. Sincerely, Nitrojc.

08-28-2009, 06:26 PM
The IPL shows a WA series Walbro carburetor,the side with just one screw holding the cover on is the fuel pump side of the carburetor. If the problem is clogged jets, then blowing air through them may do the trick. Most likely the problems is due to stiff diaphragms, a sticking inlet metering needle or a plugged filter screen in the carburetor. You won't hurt anything by trying a little compressed air 15 lbs or so should be sufficient, or even a little carburetor or brake parts cleaner (that's what I use). Usually when the circuit is clogged you just don't get any response from the adjustment screws, but it's easy enough to try and you don't have to take anything apart. If it does not help, then it's time to tear into the carburetor.

Best of Luck...

08-28-2009, 06:56 PM
30 year, In what way do you use the brake parts cleaner ? I don't know if the adjusting screws would have worked .... I left them alone.
Upon, first starting the engine, when just warm, it will run with the choke wide open, but Stumbles without pumping the throttle; then eventually dies. When hot now, it must be choked ! Thanks, Jim.

08-28-2009, 07:08 PM
I just remove the adjustment screws and attach the little straw to the parts cleaner and spray it in through the adjustment screw openings. This washes out the circuit and will generally clear up any obstruction, if there is any.

08-29-2009, 09:11 PM
Well 30 year, I found another problem upon opening the casing. The fuel line had a small tear, leaking at the carb. I cut off the bad spot, and reconnected line to carb.
I also, removed the adjustment screws for the HI / low mixture, and shot some gumout carb cleaner w/ straw thru them. The original settings were 1 1/2 open for the low, and 1 turn open for the high side. Idle screw was at 1 1/2 turns out.
I then TRIED to start the engine ............ NO START what-so-ever. Not even a sputter, until I primmed it thru the air intake w/ gumout spray. THEN IT WOULD RUN OFF THE PRIMES, BUT THAT'S IT. I haven't tried the compressed air yet, that will be next ! Unless there's a better idea short of removing the carb to clean it, or soak it.
It just seems to me that these small passageways may require a super small cleaner wire run thru them.... Maybe, a few thousands diameter would work.
Anyway, Please give me your take on this stuff. Thanks, Jim.

08-29-2009, 09:53 PM
Spray cleaner is generally all that I use on these small carburetors. I NEVER soak in bath type cleaners, as that generally does more harm then good. It has been my experience that once the fuel line springs any leaks, you might as well go ahead and replace them. They dry out and crack and leak to a point that they won't feed any fuel.

08-30-2009, 09:10 AM
Prior to finding the cracked fuel line, there was excess fuel comming out of some-where. This would happen upon shaking up the fuel mix before starting the engine. Also, noted fuel leaking out if the weedwacker was not in the upright position. Could the "duck-bill-valve" be defective ? So, I believe the line is clear to-flow-fuel. I did replace the fuel filter w/ new one. Could it be that the "Gumout brand" was ineffective ?
Besides blowing out the mixture screw holes, are there any other areas/spots to be cleared ? What about the carb air intake, you mention a screen in the carb. Also, what is the "inlet metering needle?" Is the duck bill valve a one way valve to vent the tank ?
I do have the owners manual which shows an over-all expolded view of the weedwacker, however I need more carb detail, refering to the above parts.
If you could illustrate the parts [screen/metering valve] in detail on a picture .... this would be helpful. Many-Thanks, Jim.

08-30-2009, 12:18 PM
Here is a link to the service manual for your carburetor. The filter screen I am talking about is reference # 55 in the parts illustration in the service manual.

The reason I recommend replacing the fuel line, is not because they may be plugged, but if there is any cracks or pin holes, air can enter and fuel will not flow.

08-30-2009, 05:46 PM
Thanks, 30 year. It's all much clearer to me now. Seeing the break down of the circuits, and how they operate in the walbro site. The idle screw directly meters fuel flow to the 3 ports. However, the high speed is more complicated. I am not quite sure of its operation, regarding the inlet metering needle's function. Maybe you could explain it. Rather than blow compressed air thru the mixture holes, it looks as if I could blow compressed air thru the air intake using a large rubber nozzle that would seal the opening, and with the piston @ TDC to block the back side, this also would clean out the passageways. WHAT DO YOU THINK of that idea ??
I believe your correct to insure no air leaks by replacing the fuel line is the best bet, and that is what I'll do.
Please give me your take on my idea above. Thank-You, Jim.

08-30-2009, 06:07 PM
Blowing compressed air through the carburetor inlet is not the best thing to do. It will work to free up a stuck inlet metering needle. If there is any build up or debris on the filter screen, blowing air into the inlet will only force this through the filter screen and into the main metering area of the carburetor.

Tearing down and cleaning of the carburetor is your best bet. It's not that difficult and does not take a lot of time. Short cuts sometimes work, but most often they just add to the overall time of repair.

08-31-2009, 09:42 AM
Well, If I have to remove, and tear down to clean the carb anyway, I might as well try the compressed air first. If the screen is clear, then this could work, and I'd be up and running with No teardown, Correct ? That's provided it is a stuck inlet metering needle.
Yesterday, I did try this, and it made no difference. However, I don't know if I had a good seal with the piston @ TDC. Is there another way to seal off the intake port side of the engine ? Maybe a rag stuffed into the carb past the idle port holes, or possibly a neopreme cork ? Thanks, Jim.:tongue:

08-31-2009, 06:09 PM
I was referring to the fuel inlet, not the air inlet to the carburetor. There is a check valve in the main jet that prevents positive pressure from the air inlet to enter the metering chamber of the carburetor, so this would not work.

09-01-2009, 10:10 AM
30 year, I really don't mean to beat this stuff to death, but I must know/learn the functions of the internal parts. Even if I tear down the carb, what parts/passages will be the focus to clean ?
Just reciently, I had a very similiar problem with a 5hp. Briggs engine, it also would only run on primes. It turned out to be a restricted main-jet in the fuel bowl nut. After cleaning it with a serrated wire of the proper size it runs now. Even though the two carbs are different, the principle is the same, just different parts. That is why, I believe in focusing-in on specific areas to fix the problem.
Parts like the Duck-bill on the fuel tank and the inlet metering valve are not defined, and what purpose do they serve ? I'm eliminating the fuel pump diaphram because there is no flooding. Yes, possibly it does stick ..... a little WD40 should take care of that. Most likely Brake parts cleaner is Superior to Gumout carb spray cleaner.
My Best guess at this point .... Restricted, or plugged main jet, and idle ports. If I should take the carb apart to throughly clean ...WHAT DO I USE ??
THANKS .......:wave: Your Student, Jim.

09-01-2009, 02:54 PM
On this particular carburetor, it's likely a plugged filter screen that is restricting the flow of fuel into the metering chamber. The fuel pump diaphragm is probably not the problem. Gumout carburetor cleaner if fine, I have used it in the past and is alright. Unless you find a lot of debris and or varnish in the carburetor when you take it down, a simple spraying with the cleaner will generally do the trick. Remove the inlet metering needle and filter screen and make sure the passage from the screen to the needle is clear. Make sure fuel will pass through the filter screen (this part I usually replace). Check the metering diaphragm and make sure it's soft and pliable and that the pin in the middle is not separated from the diaphragm. Remove the high and low speed adjustment screws and spray cleaner though their passage ways. Replace any bad parts if needed, then reassemble and you should be in good shape.

09-02-2009, 09:30 PM
Well .... 30 year, I now feel somewhat confident doing the tear down. However, where the samhill do I get replacement parts, I have already lost the idle needle spring, and am using a pen spring in its place..
I live in Westland Mich. just out of the Detroit metro area. Hey, How bout those Tigers !!! Maybe this year is the year.
I"m counting on you for a parts store for replacement parts. I hope they are available locally, because mai order shipping is a Joke !
Thank-You for your time, and expertise, Jim

09-02-2009, 10:41 PM
Your best bet would be a complete kit. They are not overly expensive around $12.00 and most any small engine / lawnmower shop should have them. Your carburetor uses a very common kit K10-WAT. Most any dealer that handles Poulan products should have this. If you can't locate one. Let me know and I will see if I can help.

09-03-2009, 10:40 AM
30 year, The SEARS MODEL 234.795410 / CARB NUMBER 10403-01 has No primer bulb. ARE YOU POSITIVE the replacement kit K10-WAT MATCHES UP WITH MY CARB ??
I did find several carb kits [k10-wat] on E-BAY at a Good price, but None of them have the needle screw springs, so where do I get them. Thanks, Jim.:dude:

09-03-2009, 12:23 PM
K20-WAT is the kit for the carburetor with the purge bulb, and will work on Carburetors without it as well, the K10-WAT should work fine on yours. The springs do not come in the kit and have to be purchased separately.

A small engine shop generally has a grave yard full of old hand held 2 cycle equipment. I bet they would let you take the springs off an old no good unit.

09-03-2009, 07:00 PM
I know you don't believe in compressed air to clean things, but I just tried it on the Hi speed mixture screw, and it seems to have helped. It still won't run yet, but it does start without a manual prime thru the air intake.
This is the way it was last year this time, but then I primed it thru the spark plug hole ..... Each time it ran a little longer. Finally it was running on its own. However, under load the throttle had to be pumped at times. When it got hot, it would stumble, I thought it was a bad spark plug.
So, this spring I replaced it with a new one, which made No difference.
6 weeks later the wacker would barely run at all .... This is where I am today.
Watch that compressed air around 30 year old paint, It has blown areas of the paint right off the casing; this has never happen before.
As for the springs, I think my plumbing faucet stuff has the same type of springs.
My mistake, I think some of the E-Bay listings are in error.
When it comes to taking the carb apart, are there Any special tools that I may need ? ITS SOOOO CLOSE TO RUNNING !! Thanks, Jim.

09-03-2009, 08:57 PM
I have no problems with compressed air, just have to be sure where you are putting it, that's all. Should be able to do it all with just a screw driver. A stiff metering diaphragm could cause all the issues you are describing, but I would replace the filter screen anyways.

09-04-2009, 05:05 PM
To all out there, with similiar carb problems, such as I had. DON'T "WASTE YOUR MONEY ON A CARB REBUILD KIT." forget about spraying carb cleaner thru the mixture screw holes, as that won't work ! Instead use compressed air at a high setting, and blow out the openings, being careful not to pressurize the orifice opening. I also, blew some air thru the air-inlet opening, to insure it was clean/free of any particles.
This is the Best my weedwacker has run in 30 years ! I have full power through-out the entire throttle range, with a perfect idle, and all it cost me was my time, and effort. Many Thanks, to All the People on the Forums that made this Happen. Sincerely, Nitrojc.

09-05-2009, 01:26 PM
To all out there, with similiar carb problems, such as I had. DON'T "WASTE YOUR MONEY ON A CARB REBUILD KIT." forget about spraying carb cleaner thru the mixture screw holes, as that won't work ! Instead use compressed air at a high setting, and blow out the openings, being careful not to pressurize the orifice opening. I also, blew some air thru the air-inlet opening, to insure it was clean/free of any particles.

It's great that you got your weed trimmer going again, I am glad.

It's not very likely that many could repair a carburetor that is dirty or has old diaphragms, faulty check valve, or clogged circuits, simply by using compressed air. It really depends on the actual problem plaguing the carburetor. Spraying cleaner through the mixture screws will work, if they are varnished with old fuel, purchasing a kit may be necessary if the metering needle is bad and or diaphragms need to be replaced. Procedures and parts are going to be specific to each individual issue and not very generic (even though symptoms may be similar).

Today's fuel with alcohol and alcohol derivatives can cause numerous problems on internal carburetor parts. The best way to determine what is needed, is with a tear down and visual inspection of the individual components. Compressed air can inflict as much damage as it may also cure, if one is not careful.

I know from your previous posts, that you don't like to replace parts, and I agree that it's not always necessary. However, most often, you just cannot avoid the inevitable tear down. You can always try making it work without new parts, but unless you know the reason it stopped working in the first place, then you won't know what needs to be done to repair it.

The bottom line here is, your trimmer is running. Do you actually know why it stopped, and why what you did cured it?

I hope it continues to run well for you... :thumbsup:

09-07-2009, 10:50 AM
Granted these little carbs can develope multiple problems; I believe mine came down to two that I can identify. First, I found a bad crack in the fuel line, and secondly, the High speed mixture screw passageway was Restricting fuel flow.
You, suggested replacing the fuel line, which I agreed with [will replace later]. When it comes to carb spray cleaners, some are better than others. I did spray gumout brand thru the low/high orificies very liberally, then reinstalled the screws, and pulled the starter for hours with no results ! Next, I tried compressed air at a High setting, again blowing out the orificies, But Not Sealing the Nozzle to Opening, leaving a 1/2" Gap between the two. After this, the wacker engine would run without manually priming it, just by using the choke as designed.
IN FAIRNESS -- This may have been a combo effort that worked. However, Without ... BLOWING IT OUT ---The gum/varnish would have remained the restriction !!:dude:

05-28-2010, 07:42 AM
Hello 30 year, It's been almost a year now, and I have used the weedwacker a couple of times. However, I have another fuel leak, as I did before. This time as I mentioned before, I will replace the fuel line w/ new tygon. The reason I am posting this time is because ... there is No Bad spot in the line to be found, and yet it leaks fuel like there should be. What else could be causing this leak ? ..... Remember there is only one fuel line, and No primer bulb. I don't think a faulty "duck valve" would cause it.
Is there any possibility somehow the fuel is "Over siphoning" itself from the fuel tank when cranking the engine causing it to flood ?
Please give me your take on this new discovery. Thanks, Nitrojc.

05-29-2010, 01:50 AM
Have you checked the fuel cap? I recently worked on a Homelite trimmer and when tilted it would leak fuel from the cap and run down onto your hand. Replaced the cap with a new one and that fixed it.

05-29-2010, 09:18 AM
Yes, Junebug I checked the cap ... No leaks.

05-30-2010, 11:16 PM
Hello People, Somehow the duck bill valve fell out or desolved itself over the years. Where can I get one for my Sears 25.00cc model # 234.795410 WEEDWACKER ?? Thanks for any Help in locating this Valve. Nitrojc.

05-31-2010, 01:58 AM

Available from Sears Parts Direct, Jacks Small Engines, or just about any small engine dealer that handles parts for Poulan/Weedeater or Husqvarna.