Echo CS-400 Help

[PJP]

Another thing, I was priming bulb the other day and fuel was spilling out of vent... Could this have anything to do with the problem? I wonder if it is sucking air from somewhere causing it to run lean.

 

[PJP]

Here is where I am at:

If you notice, I pulled the bar & chain off. Also, once I let off of the gas the saw dies out and is impossible to start again unless I let it sit for some time not to mention it is always hard to start anyways... Before this video I was able to choke it and start it, choke it and start it, choke it and start it multiple times but would not stay running at all. After I pulled bar and chain off I was able to at least get it running until I let off of the gas.

 

[Goofaroo]

Another thing, I was priming bulb the other day and fuel was spilling out of vent... Could this have anything to do with the problem? I wonder if it is sucking air from somewhere causing it to run lean.

You could very well have an air leak but I’m guessing you need to service the carb more thoroughly. Did you completely disassemble it when you cleaned it? Did you replace any parts? If the diaphragm has hardened it will never work right. A rebuild kit will pay dividends in bringing your saw back to life.
While you have the carb off make sure the intake gasket is in good shape. Apply a thin layer of grease to the gasket to help it seal when you reinstall the carb.
Since you’ve gotten this saw to start and idle, I would be inclined to think that the saw is healthy and just needs for the carb to cooperate.

 

[PJP]

I purchased a new carb for $40.00 from Echo dealer and replaced... The primer bulb seems to be working better and I got the saw started and idled for about a minute... I gave it throttle and when I got off the throttle it bogged down and have not been able to get it started since .... Do you think it could be an engine problem? Thanks,

Peter

 

[Deleted member 149229]

Have you pulled the muffler and looked at the piston?

 

[Goofaroo]

Is the spark arrester clean? Can you get it to rev with the choke partially closed? Are you sure the chain brake isn’t engaged? Fresh and properly mixed fuel? Is it producing a good spark?

Like Dahmer said, look at the piston for any obvious damage but if it looks good and the engine rotates smoothly and has good compression it is probably fine.

Keep at it. There is most likely a simple fix and you’ll find it eventually.

 

[Okie294life]

Is the spark arrester clean? Can you get it to rev with the choke partially closed? Are you sure the chain brake isn’t engaged? Fresh and properly mixed fuel? Is it producing a good spark?

Like Dahmer said, look at the piston for any obvious damage but if it looks good and the engine rotates smoothly and has good compression it is probably fine.

Keep at it. There is most likely a simple fix and you’ll find it eventually.

Check the carb gasket to make sure that if it has a hole in it for the impulse it’s lined up correctly and check the fuel tank vent.

 

[PJP]

Hey Everyone,

Thanks to all who have given advice here. After messing with the original carburetor settings, putting in a new carburetor and everything else I've thrown at the saw it ended up being a worn / scored piston. Attached are some photos of the piston. I replaced the entire engine with an older engine out of the other used CS400 I had gotten (parts only saw) and it is working now! This new piston is not scored and looks to be in good shape. Thanks again!!

Now to figure out how to get a larger guide bar on here with the small 8mm studs that come stock.

 

[Deleted member 149229]

Scored is an understatement.