This is my first post attempt on Chainsaw Repair so will give it a shot.
I have an ECHO CS-440EVL, very low hours, historically has started and run like a new chainsaw. On recent use it began to behave as though is was leaning out. Carb. adjustment attempts had little affect.
Checked the normal items, fuel filter-not too good, fuel intake hose-spongy and fragile in area below normal fuel level, carb-not much use, but saw is several years old, both diaphragms stiff, fuel inlet screen-covered with loose, but considerable Debris, intake adapter-found with quarter inch slit in adapter neck. As indicated, found potential issues so decided to replace fuel filter, lines, rebuild carb, cleaning thoroughly, replaced diaphragms gaskets and inlet screen, replace intake adapter.
All work went very well, everything hospital clean. Tore down saw to the point needed to replace the items mentioned above. Following reassembly, fueled unit and added chain oil. Everything had gone so nicely, expectation was for good start and after carb adjustment I was looking forward to a like new chainsaw.
Upon start attempt, it popped after the first pull. There was no second pull, piston was locked in position. Did a little careful testing and nothing was moving. Removed carb., and in that process I noticed that a small lock washer and a small standard washer were missing off of one stud that connects the carb. body to the adapter plate. At that point I experienced an unspeakable sinking feeling and upon further examination down the intake I could see a small dent on the piston skirt and a shallow scrape on the side of the piston.
These observations meant I needed to tear the saw down to a point at which I could determine the extent of the damage. That is the reason for my post. I have not torn a saw down beyond the point of changing a piston and cylinder head. This involves removing the crank, splitting the crank case and advice in those areas would be appreciated. I have searched the threads and was unable to locate one describing the processes mentioned above.
Presently, the saw is disassembled to the point of removing the cylinder head, the piston, the clutch assembly from the crank shaft and of course all miscellaneous items required to gain access to these last items mentioned. Amazingly, the only thing that is definitely toast is the piston, having multiple small chunks broken off and the rings are in several peaces. Multiple small portions of piston and ring material have been found and removed. Nothing else appears to be damaged, but the crank is still in the crank case so problems with the bearings or in the bottom of the crank case are possible.
Now, questions and/or recommendations:
1. Remove the flywheel via supporting the flywheel and with brass
hammer, tap the flywheel end of the crank to release flywheel or
use standard two armed puller and remove the flywheel?
2. Procedure to separate the case. Remove bolts, and carefully
bump the case with a rubber hammer to separate halves?
3. When reassembling the crank case using a gasket, should
some type of gasket compound be applied to the gasket to assist
in the assembly process and improve the final seal quality?
That is my present situation and those are the primary concerns that come to mind at this point in time. If you have any suggestions or concerns I would definitely appreciate your input.
I have been told this is the forum most likely to provide high quality information and guidance in dealing with chainsaw problems. thus my arrival on this forum and on this thread, hopefully, I have selected the appropriate thread.
Your assistance in helping me attempt to bring this very good ECHO chainsaw back to life would be sincerely appreciated. If needed, I will attempt to provide pictures, depending upon my ability to figure out how to upload pictures to the site.
Nick, North West Farmer