Craftsman weedeater won't stay running...maybe it's not hungry?

St8shooter

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I have a green Craftsman weedeater, ($99.model) thats only a few years old and has been well taken care of. I can start it and run it for about 30 seconds and then it dies. Also, I have to put the choke lever between full and half to start it and it won't run at all if it is not in that position. Any suggestions?
 

wildbill

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I assume the gas tank is clean, new gas in it...... Likely the carb needs cleaning...... on the inside. You can disassemble it and go through those pains to clean it with some carb cleaner... OR, get a spray can of carb cleaner and a piece of gas line the size of the one on the carb at the nearest parts store. Unless you have some real trash inside, you can do a 'quickie' by pulling off the gas line where it enters the carb, attach a same-size gas line about 6" long to the carb, spray it full of the carb cleaner, let it enter the inside of the carb with gravity. Let it sit for a minute or so. Remove the 'fix-it' line, hook up the gas line and fire it up. This works about 99% of the time.... and, this is a good thing to do at the beginning of each season..... ps, it also works great on the mower too.
 

St8shooter

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I appreciate your suggestion. Everything is clean and the gas is fresh. Its like once it warms up, it just wont keep running and it powers down.
 

goodolboydws

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I appreciate your suggestion. Everything is clean and the gas is fresh. Its like once it warms up, it just wont keep running and it powers down.

Was it running well and then one day it suddenly began doing this, or did it gradually get worse?

First thing that I'd check now would be the fuel filter-if you can fish it out of the tank that is. You should be able to blow through it fairly easily via a fuel line. If not, replace it. There's enough fuel in a carb and in the fuel line for an engine to run for a while, even if the filter is partially blocked and can't allow enough fuel through to keep up with the engine by itself, so the engine will then run until the amount that's slowly getting through the filter isn't enough to keep it running, it could be as simple as that.

If this situation got gradually got worse, after the filter check, try pulling out the clean, re-gapped spark plug (you already did that, right?) and looking at the top of the piston for a carbon buildup there. There's usually some, but there could be a lot-and it might even look crusty. I'd then check the muffler and then finally the exhaust port for possible carbon build up there too. INSIDE many newer mufflers there's a fine metal mesh screen that can easily get carbon blocked (older models often didn't have any screen, then sometimes a coarse one, now a fine one). I've heard that some people remove this screen when it gets blocks, not that I'd recommend doing that, (because it functions as a spark arrestor), but cleaning it would be a good thing even if it's not completely carboned up. If there's any build up, it will limit the amount of air that can flow through the engine, which then limits the amount of fuel that can be pulled through, if the blockage is serious, the problem gets worse. For example if half the exhaust port is crud blocked, the engine may not run at anything above half speed, and may only stay running with difficulty, dies easily under load and runs "best" with the choke half closed.

On many/most line trimmers the exhaust port is easily accessible once the muffler is off-you should be able to look directly into it to see the shiny side of the piston. (You may have to change the piston's position by slowly turning the cutting head or pullingthe starter cord slowly with the spark plug out if you can't see it.) For a typical sized trimmer engine, a slot about the width of a nickel and in the center taller than one is thick should be visible. If not, and especially if the edges of the slot look very much narrower than the center does, the odds are strong that the port is partially blocked with burned-on carbon from partly un-burned oil from the fuel mixture.

A hard coating of carbon in the ports' opening can be very difficult to remove without damaging the aluminum of the port or the piston, unless you have a light touch and the right shaped tools-but it's worth a look and if the machine is down due to it, even removing a significant part of the accumulation will make a noticible difference in how the engine runs. Changing the shape and size of the exhaust port can have a large and often negative effect on the engine's performance, so it's best to try to avoid changing it at all by avoiding any very hard or too-aggressive grinding or filing tools, especially any high speed ones. I've used dental-handled type hand tools, (scrapers and mini chisels) and a Dremel tool with a fine wire end brush afterwards to smooth out some of my scratches afterwards. Some people would use an abrasive impregnated rubber bit or a hard felt "bob" and extremely fine grit polishing media to polish the port area. To be sure to get most of your cleaning debris out, have the spark plug out and the piston port fully open, first flush with spray carb cleaner through the spark plug hole and then blow out the piston and cylinder wiith compressed air before closing it up afterwards.
 
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wildbill

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
Some real good points and suggestions from the last thread. If cleaning the carbon fixes it, all is well. If not, the eater is starving for fuel. I would suggest replacing the gas supply lines. They come in a kit for about 10 bucks. One could have a pin-hole, the filter may have ethanol deposits on it, etc. But, before you spend the 10 bucks, carefully, disassemble the carb. There are some really small passages (ports) through which gas-air must be able to pass. There is also (usually) a small needle & seat with a little spring. Take pics as you go so the assembly will go right. There is also a couple diaphragms that must be placed back in the right sequence. All this is done by removing 4 or so screws. The parts are not expensive if needed. I was just 'donated' a 2 year old Troy-Built weed eater last week. Same problem as yours. The problem was the deposits left by the crap gas we now have, the ethanol. I cleaned the carb, all is well. PS- Use high-test gas.
 

St8shooter

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
Some real good points and suggestions from the last thread. If cleaning the carbon fixes it, all is well. If not, the eater is starving for fuel. I would suggest replacing the gas supply lines. They come in a kit for about 10 bucks. One could have a pin-hole, the filter may have ethanol deposits on it, etc. But, before you spend the 10 bucks, carefully, disassemble the carb. There are some really small passages (ports) through which gas-air must be able to pass. There is also (usually) a small needle & seat with a little spring. Take pics as you go so the assembly will go right. There is also a couple diaphragms that must be placed back in the right sequence. All this is done by removing 4 or so screws. The parts are not expensive if needed. I was just 'donated' a 2 year old Troy-Built weed eater last week. Same problem as yours. The problem was the deposits left by the crap gas we now have, the ethanol. I cleaned the carb, all is well. PS- Use high-test gas.

Thanks, I will give it a try. I haven't had a chance to mess with it lately but I will.
 

St8shooter

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
Was it running well and then one day it suddenly began doing this, or did it gradually get worse?

First thing that I'd check now would be the fuel filter-if you can fish it out of the tank that is. You should be able to blow through it fairly easily via a fuel line. If not, replace it. There's enough fuel in a carb and in the fuel line for an engine to run for a while, even if the filter is partially blocked and can't allow enough fuel through to keep up with the engine by itself, so the engine will then run until the amount that's slowly getting through the filter isn't enough to keep it running, it could be as simple as that.

If this situation got gradually got worse, after the filter check, try pulling out the clean, re-gapped spark plug (you already did that, right?) and looking at the top of the piston for a carbon buildup there. There's usually some, but there could be a lot-and it might even look crusty. I'd then check the muffler and then finally the exhaust port for possible carbon build up there too. INSIDE many newer mufflers there's a fine metal mesh screen that can easily get carbon blocked (older models often didn't have any screen, then sometimes a coarse one, now a fine one). I've heard that some people remove this screen when it gets blocks, not that I'd recommend doing that, (because it functions as a spark arrestor), but cleaning it would be a good thing even if it's not completely carboned up. If there's any build up, it will limit the amount of air that can flow through the engine, which then limits the amount of fuel that can be pulled through, if the blockage is serious, the problem gets worse. For example if half the exhaust port is crud blocked, the engine may not run at anything above half speed, and may only stay running with difficulty, dies easily under load and runs "best" with the choke half closed.

On many/most line trimmers the exhaust port is easily accessible once the muffler is off-you should be able to look directly into it to see the shiny side of the piston. (You may have to change the piston's position by slowly turning the cutting head or pullingthe starter cord slowly with the spark plug out if you can't see it.) For a typical sized trimmer engine, a slot about the width of a nickel and in the center taller than one is thick should be visible. If not, and especially if the edges of the slot look very much narrower than the center does, the odds are strong that the port is partially blocked with burned-on carbon from partly un-burned oil from the fuel mixture.

A hard coating of carbon in the ports' opening can be very difficult to remove without damaging the aluminum of the port or the piston, unless you have a light touch and the right shaped tools-but it's worth a look and if the machine is down due to it, even removing a significant part of the accumulation will make a noticible difference in how the engine runs. Changing the shape and size of the exhaust port can have a large and often negative effect on the engine's performance, so it's best to try to avoid changing it at all by avoiding any very hard or too-aggressive grinding or filing tools, especially any high speed ones. I've used dental-handled type hand tools, (scrapers and mini chisels) and a Dremel tool with a fine wire end brush afterwards to smooth out some of my scratches afterwards. Some people would use an abrasive impregnated rubber bit or a hard felt "bob" and extremely fine grit polishing media to polish the port area. To be sure to get most of your cleaning debris out, have the spark plug out and the piston port fully open, first flush with spray carb cleaner through the spark plug hole and then blow out the piston and cylinder wiith compressed air before closing it up afterwards.

Thanks, I will give it a try. Sorry for the slow response back.
 

Jeep Man

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I have the same problem on a 25 cc Craftsman weed wacker. It starts fine but after 5 minutes or so, it dies and I have to leave the choke on to get it to run. I removed and cleaned the muffler and cleaned the exhaust port. I removed the filter to see if that helped. No difference. The spark plug is new. I hate to spend $35 on a new carb if that isn't the problem. Any ideas, replace gas lines and clean carb?

Thanks
 

DaveTN

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
I have the same problem on a 25 cc Craftsman weed wacker. It starts fine but after 5 minutes or so, it dies and I have to leave the choke on to get it to run. I removed and cleaned the muffler and cleaned the exhaust port. I removed the filter to see if that helped. No difference. The spark plug is new. I hate to spend $35 on a new carb if that isn't the problem. Any ideas, replace gas lines and clean carb?

Thanks

On weedeaters that are hard to start or difficult to keep running, I always remove the carburetor plate at the fuel inlet. Take out the diaphragm and squirt carb cleaner in every hole and make sure that tiny filter screen is open. You wouldn't believe the amount of crud that accumulates in them! Once you have clean fuel from Tank...>....Fuel Line...>...Carburetor Inlet...
Internal Filter....> to finally Seat and Needle, it should run. Assuming there are no internal orifices blocked with varnish or dirt. Most of the time I can get one running by cleaning it with carburetor cleaner. Be sure to wear eye protection as it's no fun getting shot in the eyes with carb cleaner! Hope this helps.
 

Jeep Man

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  • / Craftsman weedeater won't stay running...maybe it's not hungry?
Thanks, I'll pick up some carb cleaner and try that today. I appreciate the advice.
 
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