Echo timberwolf cs-590 fuel leaks out of compression switch

[cycloptico]

Hey yall, new here, first post, my Forman picked up an an echo timberwolf cs-590 from a homeowner whose property we were on for 200$. The saw was brand spanking new, the home owner had bought it new, used it once on one tree, fell it, and could not start it again. Neither could my crew after it was bought. Even the white hats didn't know what was up so I'm curious to see if any of you might know the issue. So using proper starting procedure, can't even get it to kick, after about 4 pulls its flooded, spark plug has been replaced, flywheel is good (generates a strong spark with tester) spark plug is good. When I pull the start cable with the spark plug out it flings loads of gas out like a spray bottle, after about 8 - 9 pulls its a faint mist, I wipe the spark plug dry, put it back in, 3-4 pulls flooded, but there is gasoline coming out of the compression toggle. Not sure what silly thing the previous owner may have done but that shouldn't be happening. I've not tried a carb adjustment quite yet cause I get home late but it seems this may be something else. Anyone got some good input?

 

[atpchas]

Check whether the metering needle is seating correctly. That's the most obvious source of so much fuel coming in after so few pulls.

 

[Gord404]

Check whether the metering needle is seating correctly. That's the most obvious source of so much fuel coming in after so few pulls.

I agree and a very easy saw to work on.

 

[ChasSC]

When I first bought mine (brand new), it was literally impossible to start, flooding like you described. I finally realized the decompression valve was sticking open. Going thru the start-up procedure, I would have to pop the decompression valve closed with a small flat head screwdriver. Went to dealer, told him it was bad, he didn't even look at the saw, just ordered a new one under warranty. When I was starting to replace it, I just sprayed some liquid graphite on the shaft after removing the cap. Let it sit and evaporate the liquid, started up on third pull and functioned perfectly. Now I have a new extra decompression valve, and haven't had a problem since.

 

[pioneerguy600]

Some Good input? This saw is a perfect candidate for some diagnostic testing, compression test will reveal if there is enough to start the engine and show if the decomp valve is faulty. A quick vac and pressure test will tell if the airtightness of the unit is tight or leaking. The carb should be taken apart and inspected for debris in the fine screen , stiff diaphragms, proper adjustment of the metering lever and a final pressure test to see if the needle is closing tight, that prevents flooding most times. It has been said the engine has good spark but it will not fire up, if it is flooding out too early it won`t start. Without doing some testing it is just guess work and throwing parts at the perceived problem. Taking the muffler off and looking at the piston will tell most experienced mechanics the state of the piston, rings and cylinder , it is one of the first things I do myself before going deeper into the engine, its not all that difficult and costs nothing but a bit of time.

 

[cycloptico]

Thanks for all the input, the metering needle seems to be fine, I will try a new decomp valve, however a new questionable thing has arisen while trying to deflood the engine, while pulling the cable with the sparkplug out, bits of rubber flew out of the hole which looks like pieces of a gasket, so my curiosity has peaked and I'm just gonna take the hole damn thing apart, also how can I tell where the metering needle needs to be?

 

[pioneerguy600]

Thanks for all the input, the metering needle seems to be fine, I will try a new decomp valve, however a new questionable thing has arisen while trying to deflood the engine, while pulling the cable with the sparkplug out, bits of rubber flew out of the hole which looks like pieces of a gasket, so my curiosity has peaked and I'm just gonna take the hole damn thing apart, also how can I tell where the metering needle needs to be?

Take the carb out, let us know what make and model it is, then one of us will tell you how to set the metering lever. It depends on the make and model of carb. Some set level with the bottom of the fuel bowl while others sit flush with the machined off surface of the carb body.

 

[ChasSC]

Thanks for all the input, the metering needle seems to be fine, I will try a new decomp valve, however a new questionable thing has arisen while trying to deflood the engine, while pulling the cable with the sparkplug out, bits of rubber flew out of the hole which looks like pieces of a gasket, so my curiosity has peaked and I'm just gonna take the hole damn thing apart, also how can I tell where the metering needle needs to be?

You don't need to replace the decompression valve yet, just make sure it's popping out when you get that first fire (pop).

 

[cycloptico]

You don't need to replace the decompression valve yet, just make sure it's popping out when you get that first fire (pop).

I don't get a first fire

 

[cycloptico]

Take the carb out, let us know what make and model it is, then one of us will tell you how to set the metering lever. It depends on the make and model of carb. Some set level with the bottom of the fuel bowl while others sit flush with the machined off surface of the carb body.

Will do, I'll take pictures as well

 

[Wood Doctor]

Some Good input? This saw is a perfect candidate for some diagnostic testing, compression test will reveal if there is enough to start the engine and show if the decomp valve is faulty. A quick vac and pressure test will tell if the airtightness of the unit is tight or leaking. The carb should be taken apart and inspected for debris in the fine screen , stiff diaphragms, proper adjustment of the metering lever and a final pressure test to see if the needle is closing tight, that prevents flooding most times. It has been said the engine has good spark but it will not fire up, if it is flooding out too early it won`t start. Without doing some testing it is just guess work and throwing parts at the perceived problem. Taking the muffler off and looking at the piston will tell most experienced mechanics the state of the piston, rings and cylinder , it is one of the first things I do myself before going deeper into the engine, its not all that difficult and costs nothing but a bit of time.

I ran into something like this with a Stihl MS360. The decomp valve had perhaps stiffened up a bit and all it took was some grime collected between the valve and the shroud to prevent the valve from popping up and thus disengaging. So, it never fired and we thought it was a straight-gassed piston/cylinder. When I replaced the decomp and cleaned out the grime, I tried starting again and it fired and operated perfectly.

Needless to say, that was a pleasant, unexpected discovery.

 

[pioneerguy600]

I ran into something like this with a Stihl MS360. The decomp valve had perhaps stiffened up a bit and all it took was some grime collected between the valve and the shroud to prevent the valve from popping up and thus disengaging. So, it never fired and we thought it was a straight-gassed piston/cylinder. When I replaced the decomp and cleaned out the grime, I tried starting again and it fired and operated perfectly.

Needless to say, that was a pleasant, unexpected discover

Carbon on the valve stem or seat is the most common mterial I find preventing valves from sealing tight. It`s easier to just pop another in and be done with it but if one has time they can be cleaned and put back in service.

 

[Stihl Sharp]

After the carb fix, do a coil test on it while you`re at it.
My suspicion is that they left ethanol gas in it and it gummed up the saw from sitting. Clean the fuel tank & hoses, i`ll bet it probably needs it.
Leave the decompressor valve alone. Just make sure its moving in an out manually. Gas is escaping thru the decompressor valve because it is so flooded.

 

[cycloptico]

Take the carb out, let us know what make and model it is, then one of us will tell you how to set the metering lever. It depends on the make and model of carb. Some set level with the bottom of the fuel bowl while others sit flush with the machined off surface of the carb body.

Alright I finally got some time, here's pics of the carb, and needle

 

[ballisticdoughnut]

Make sure the metering lever is flush with the carb body. Looks a little funny in the picture but could just be the angle.

 

[cycloptico]

Make sure the metering lever is flush with the carb body. Looks a little funny in the picture but could just be the angle.

With the body not the shield?

 

[cycloptico]

With the body not the shield?

I haven't touched it yet, so just to be clear are you telling me to bend the lever so it's flush?

 

[ballisticdoughnut]

With the body not the shield?

Yes with the body of the carb, as shown in the picture

 

[Sidecarflip]

Yep, use a metal ruler or straight edge.

 

[cycloptico]

Yes with the body of the carb, as shown in the picture
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