I have five of them sitting on my garage floor. One runs like there's no tomorrow. One runs only if you keep gassing it. Three start, rev once and die. The carbs are clean (very clean), the metering diaphrams are clean and flexible, the gas lines are perfect, the ignitions produce very nice spark, the tanks are vented nicely, the fuel filters are clean and clear. I'm stumped. I've heard (here sometimes) that the carbs on these things just go bad and there's nothing you can do about it. Any ideas? ARRRRRRRRRRRGH!
Echo CS-301 Chainsaw
- Thread starter yeehaw1960
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Have you actually put kits through the carbies of any of the non runners ?
Have you checked the metering lever heights ?
Have you checked the pulse lines ?
The one that starts and only runs at full throttles sounds like a blocked LS circuit or or an air leak.
Have you pressure tested the saws ?
A bad base gasket, carb boot or crank seals can give these sort of symptoms too.
I'd carefully check for an air leak.
You can strip the carby, take the jets right out and blast carby cleaner and if careful, compressed air through the circuit to clean.
In the case of bad blockages the internal welch plugs can be removed, the circuits cleaned and new plugs installed and peened.
What make/model carburettor ?
Have you checked the metering lever heights ?
Have you checked the pulse lines ?
The one that starts and only runs at full throttles sounds like a blocked LS circuit or or an air leak.
Have you pressure tested the saws ?
A bad base gasket, carb boot or crank seals can give these sort of symptoms too.
I'd carefully check for an air leak.
You can strip the carby, take the jets right out and blast carby cleaner and if careful, compressed air through the circuit to clean.
In the case of bad blockages the internal welch plugs can be removed, the circuits cleaned and new plugs installed and peened.
What make/model carburettor ?
I've got a 5 year old Echo CS-346 (very similar) that hasn't missed a beat in all the years I've owned it. However, I removed the catalytic converter from it and removed covers (locks) for the carburetor adjustment screws to allow me to set it for more power. It starts well and runs better than it did in stock form.
What do the tops of the pistons look like? What do the spark plugs look like?
If the fuel system is in good working condition, make sure the exhaust is clear and all possibilities of a crankcase leak are eliminated.
What do the tops of the pistons look like? What do the spark plugs look like?
If the fuel system is in good working condition, make sure the exhaust is clear and all possibilities of a crankcase leak are eliminated.
123Saab...you're a genius. Simple yet effective way to check the other carbs. Will do it tomorrow. Thanks!
Put the carb from the running machine onto the non-running machine and it purred like a kitten. Rebuilt the carb on the non-running machine from head to toe, replacing every part, and the machine still didn't run. Looking for a new carb.
Thanks guys!
Thanks guys!
Originally Posted By: yeehaw1960
Put the carb from the running machine onto the non-running machine and it purred like a kitten. Rebuilt the carb on the non-running machine from head to toe, replacing every part, and the machine still didn't run. Looking for a new carb.
Thanks guys!
Do those saws have Zama carbs?
Put the carb from the running machine onto the non-running machine and it purred like a kitten. Rebuilt the carb on the non-running machine from head to toe, replacing every part, and the machine still didn't run. Looking for a new carb.
Thanks guys!
Do those saws have Zama carbs?
It's a Walbro. I wonder if I'm missing some fuel or air passage somewhere, but couldn't begin to figure out where.
Originally Posted By: yeehaw1960
It's a Walbro. I wonder if I'm missing some fuel or air passage somewhere, but couldn't begin to figure out where.
I just bought a kit for a Walbro carb on a Stihl 024 Wood Boss saw. Kit came with a million parts but I only used four. Upper and lower diaphragm and gaskets.
Before installing them, I pulled the mixture screws and blew WD-40 though them and made sure that I saw it come out the orifices in the carb venturi. Then blew them clear with compressed air. Replacing the tiny lever and spring for the fuel inlet needle is a p.i.t.a. The little spring is difficult to keep in place. I got around that problem by gluing it down with some general purpose grease.
Got the saw running much better but still need to fine tune it.
Make sure your fuel line to the carb isn't leaking and the vacuum line to the carb is also in good condition.
It's a Walbro. I wonder if I'm missing some fuel or air passage somewhere, but couldn't begin to figure out where.
I just bought a kit for a Walbro carb on a Stihl 024 Wood Boss saw. Kit came with a million parts but I only used four. Upper and lower diaphragm and gaskets.
Before installing them, I pulled the mixture screws and blew WD-40 though them and made sure that I saw it come out the orifices in the carb venturi. Then blew them clear with compressed air. Replacing the tiny lever and spring for the fuel inlet needle is a p.i.t.a. The little spring is difficult to keep in place. I got around that problem by gluing it down with some general purpose grease.
Got the saw running much better but still need to fine tune it.
Make sure your fuel line to the carb isn't leaking and the vacuum line to the carb is also in good condition.
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