I have a CS-8000 that I've never had an issue with except for a minor fuel leak from around the base of the tank vent which I fixed yesterday by sealing it with jb weld. Now I go to cut today and the saw runs fine for 2 or 3 cuts on some 24"+ elm and then just bogs down and dies. Now the saw will start fine and idle fine but when you go give it throttle it dies. If you give it super light throttle you can get it to rev for a few seconds then dies. It still had the limiter caps and I stripped the low trying to get it out. I got the high off. Any help would be appriciated
CS-8000 Help Please, Won't Accelerate
- Thread starter jtc16
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ANewSawyer
Addicted to ArboristSite
Pop the fuel cap when it dies and then see if will throttle up. Also, check the piston for scoring.
ANewSawyer
Addicted to ArboristSite
No, but that would work. It is just...unconventional. 
Run it till it dies then loosen the fuel cap slightly. Listen for a hiss or other sound not normally present when you loosen the fuel cap. Try restarting it after loosening the fuel cap. If it accelerates after you loosen the fuel cap, there is a problem with the tank vent. I would check the piston and cylinder through the muffler port first. Just to be sure.
Run it till it dies then loosen the fuel cap slightly. Listen for a hiss or other sound not normally present when you loosen the fuel cap. Try restarting it after loosening the fuel cap. If it accelerates after you loosen the fuel cap, there is a problem with the tank vent. I would check the piston and cylinder through the muffler port first. Just to be sure.
I guess its safe to say you plugged up that vent with JB Weld? On some of the 8000 tanks there is an inside filter built into the tank where the vent line attaches, from your pics this looks to be what your working with. On other 8000 tanks the vent line plugs into the tank via a separate vertical hole (like a cs-670) near the fuel line port. The purpose of the inside filter is to keep the liquid fuel out of the vent allowing the tank to take a breath when its moved from a vertical to a horizontal like when filing the tank or felling a tree. In addition to this vent there is usually a second vent located under the handle bar support located on the right side of the tank. To access the second vent remove the 3 bolts at the bottom of the right handle support, and one more at the carb box. Then the handle support can be swung to the side exposing the second vent.
What model no. is on the plate up under the clutch cover for this unit?
The qv/cs-8000 saw has been in circulation for 32 years. I think this is why Echo came out with the 800p so they could standardize all the parts. There are several different carbs, ignitions, pistons, fuel tanks, and at least 3 different vents used on the design.
Pull the recoil (4bolts) and the air vane underneath (lifts off), remove the top cover (4bolts). Move over to where your leak was originally and find the vent line. Pull the cap off the white jelly bean with a small flatblade and take out the filter (black square foam) and the duckbill (black rubber) with the tip of the blade. You can loosen or remove the air box to tank cushion on the recoil side by removing 3 more bolts that hold it on. Pay attention to the length of those bolts when you put it back together.
Once you get the line accessible, push some air through it with your mouth and see if it vents (make sure the fuel is out and the cap is off). If it vents, leave out the filter and duckbill, put the white cap back onto the jellybean and try a few cuts. The correct service would be to replace the carb diaphragms, both fuel lines, the top vent line with the jellybean, and the vent on the right side.
What model no. is on the plate up under the clutch cover for this unit?
The qv/cs-8000 saw has been in circulation for 32 years. I think this is why Echo came out with the 800p so they could standardize all the parts. There are several different carbs, ignitions, pistons, fuel tanks, and at least 3 different vents used on the design.
Pull the recoil (4bolts) and the air vane underneath (lifts off), remove the top cover (4bolts). Move over to where your leak was originally and find the vent line. Pull the cap off the white jelly bean with a small flatblade and take out the filter (black square foam) and the duckbill (black rubber) with the tip of the blade. You can loosen or remove the air box to tank cushion on the recoil side by removing 3 more bolts that hold it on. Pay attention to the length of those bolts when you put it back together.
Once you get the line accessible, push some air through it with your mouth and see if it vents (make sure the fuel is out and the cap is off). If it vents, leave out the filter and duckbill, put the white cap back onto the jellybean and try a few cuts. The correct service would be to replace the carb diaphragms, both fuel lines, the top vent line with the jellybean, and the vent on the right side.
Ok thanks, I'll start this evening and get the model number. I'm hoping I put so much jb weld that the vent line just got pinched off when I put the cover back over it. the vent line has like a cork at the bottom so it just sticks in like a cork but the glue that sealed it originally was leaking. My jb welb is doing the same thing as the glue I think so maybe its just pinched. Don't know how I'm going to get it all off if I need too. Thanks again.
I removed the jb weld from around the vent. It wasn't hardened for some reason so it wasn't that hard. It was the gas safe kind too. I ran the saw with the white top cap off and on the vent. Same thing either way, no acceleration. I tried blowing through the vent filter, the white thing with the black foam in it. No air, I couldn't blow through it. Maybe that is clogged and having something to do with it. Here's the new thing though. Before when the vent line was pulled out you could see the screw underneath it and I did nothing to the screw. There was no fuel visible though. Now when you pop the vent line out fuel just keeps bubbling up and out. Model # below
Where in IN you located? Most Echo's are very lean from the factory. I would get the vent fixed and richen it up as you might be to lean.
Terre Haute. Where are you? I'm going to hope someone on here can help me fix it before I take it to a dealer. I hate to be suspicious but I'm not certain this problem wasn't caused by a dealer. I had a minor fuel leak when the cap was off around the base of the vent line, took it to a dealer to look at it. He pulled the vent line and told me to jb weld it in. Now the thing won't accelerate and fuel bubbles up from the screw under the vent line like it never did before.
i wouldn't go back to that dealer. first, you shouldn't need any glue. you should be able to push the breather in hard enuff so that friction will hold it. if that doesn't work switch to a grommet and straight fuel line. let me know if you can't find the part numbers. your problem with revving could be your carb. it may need new diaphragm, oneway valve, filter screen and possibly the needle valve. as rmh said, this saw could be pretty ancient and e10 may have done a job on the carb. also, look for leaks in the line between the fuel filter and the double barb fitting and the carb and double barb fitting. it could be leaking inside the tank and sucking in air. or where it exits the tank and that's the source of the gas you're seeing. some hombres on this site say that e10 doesn't cause any problems but that just isn't true. i work on a lot of saws with the same symptoms you discribe and 9 times out of 10 its damage from e10. i like to just replace the carb and fuel lines rather than rebuild. however with your saw a new carb is more than $100 so you want to try a rebuild first. you should still replace the line from the filter thru the tank. hope this helps.
brandonstc6
Addicted to ArboristSite
Look and see if your carb is a Walbro and stamped HDA. If so this should be what you need and for the price it's easily worth a shot if you feel comfortable with a carburetor rebuild.
I'm not affiliated with this seller but this seems to be the best deal.
https://www.ebay.com/itm/221915751485
carb Kit K20-HDA Husqvarna 41 44 234 242 246 254 257 261 262xp many more
Sent from my iPhone using Tapatalk
I'm not affiliated with this seller but this seems to be the best deal.
https://www.ebay.com/itm/221915751485
carb Kit K20-HDA Husqvarna 41 44 234 242 246 254 257 261 262xp many more
Sent from my iPhone using Tapatalk
Thanks for that, I'll probably try the rebuild since it's so much cheaper. Never done it before but I might be able to swing it. Been real busy today so I haven't got any further on inspecting the saw but hopefully will this weekend.
the only difficult part of a carb rebuild is reinstalling the needle valve and its spring. which is often unnecessary. you could just replace the diaphragm and one-way valve on opposite sides of the carb, replace the filter screen under the one-way valve and see if it works better. inspect the needle valve and the lever that operates it. if you're feeling ambitious, while you have the carb off remove the tray under the carb. this will give you access to all the rubber tubes. you can replace the two fuel lines and get a much better look at the breather. be sure to get the manual oiler line back on top of the tiny o-ring when you remount the tray. the "banjo" fitting on the end of the oil line has a little tit that fits in a hole to help position it. good luck!
Guido Salvage
Supreme Saw Whoreder
It has been a while since I have worked on a CS-8000 but I seem to recall some weird spring and block type assembly in the throttle linkage. Worked on one where that was the problem. Pull the air filter off and confirm that the carb is opening up when you squeeze the trigger.
I've been real busy these last few days. Got no jobs today and I have a cold or extreme allergries, not sure which, so I'm hoping to get this saw dealt with today.
What am I looking for when I make sure the throttle is opening the carb? The saw is apart, I went out there and pulled the trigger and it is linked to something on the left side of the carb and it moves it but that's about all I can tell. Do I have to take the carb apart?
Anyone know how many turns out the h and l are supposed to start at on the cs 8000? I have to crank the l up just to get it to idle. I took it all apart and cleaned the carb didn't see any broken tubes so now I'm trying to adjust it before trying the rebuild. I can get it to idle and got it to accelerate a little more before bogging down than it did before so im hoping now its maybe just out of adjustment.
I found info for the cs 680 that said 2 1/4 out on L, 1 1/8 out on H, 1/2 past touching on idle. Didn't work for me. at that setting it starts and tries to run on choke and dies when you push the choke off. I really think it just needs the proper adjustment but I can't do much until I know where to start. I also wonder if I may have damaged the adjusting screws trying to get the limiter caps off, I didn't do it very gracefully.
