Echo CS400

[brettl]

Roughly speaking, what's the minimum compression this saw can be operated on? I've got one that's only reaching 90psi after 3 pulls of the rope. Seems pretty weak to me. Has some scoring on the piston and cylinder so I wouldn't be surprised if someone ran straight gas in it.

[Andyshine77]

Well you need to keep pulling until the gauge needle stops moving. This can take a dozen pulls on smaller saws. The gauge should also have a valve in the tip for proper pressure reading. The minimum for a saw to at least start, is 100psi. Most modern saws will have anywhere from 125psi, all the way up to 200psi on the upper end. 200psi is rare on a stock saw however.     

[ladylake]

If it turns out around 90# you need a new ring for sure and maybe a piston. Most times the cylinder will clean up.  These saws really like a muff modd.  A new OEM piston cost $43 and a ring is $5.   Steve

[brettl]

Thanks Andre and Steve. I needed to be more clear in my op. No matter how many pulls, 90psi is where it tops out. 3 pulls is just where it tops out. From what I've heard of these saws, it sure sounds like a saw worth repairing. And that muffler? Feels like it weighs a pound by itself! Definitely needs some surgery. Thanks again for the replies.

[Andyshine77]

Thanks Andre and Steve. I needed to be more clear in my op. No matter how many pulls, 90psi is where it tops out. 3 pulls is just where it tops out. From what I've heard of these saws, it sure sounds like a saw worth repairing. And that muffler? Feels like it weighs a pound by itself! Definitely needs some surgery. Thanks again for the replies.

OK I see, yes 90psi isn't going to cut it. The CS400 is a nice little saw, worth a new piston for sure. Now keep in mind the 400 can be had for well under 300 bucks, so I'd make sure it doesn't have many other issues before you start buying parts. A pressure and vac test in in order, as that can cause lean condition and burn a saw up as well.

[brettl]

Yeah, end of December there was one here on cl for 200 w/case and looked pretty new. I'll keep the vacuum and pressure test in mind to, although I'd hate to pay to have that done just to find out it's not worth putting money in. I'll have to see what that service will run. Thanks Andre