Piston scored, maybe some transfer onto cylinder wall, you say.
Usually an indicator that the piston/block has overheated.
I've got a few saws that were given to me because they were not running or run poorly and reported to have low compression as to why poor operation.
And low compression was not the issue.
After looking at a piston through the exhaust port if the piston only had few scratches, not scored/scuffed/chewed on due to scrubbing on the cylinder wall I would then check the compression. If the piston is scored and scuffed due to rubbing on the cylinder wall no need in a compression test because the block has cancer and the engine is eating itself. It been hot and even after a repair with cylinder kit it may just ruin itself again if the cause is not investigated. (usually piston/block overheating is the cause of piston scuffing and happens when the saw is being used in a full bar or loaded heavy cut for more than 30 seconds) I've used a IR therometer with good results to monitor block temp to indicate if the saws block is overheating.
Usually requires a full bar loaded cut at full throttle for longer than 30 seconds to detect a chainsaw block to start overheating. Short cuts of less than 30 seconds in and out of a cut may not indicate any severe overheating and the saw may operate ok for quite awhile, but is just waiting for a overheat to occur when loaded up heavy in a full cut.
If your friend is not going to try repairing his own saw I would probably suggest to him to go get a new saw. (and quit using E10)
other option would be a 2nd opinion from another shop and not even mention the first shops opinion when going for the 2nd opinion.
Usually an indicator that the piston/block has overheated.
I've got a few saws that were given to me because they were not running or run poorly and reported to have low compression as to why poor operation.
And low compression was not the issue.
After looking at a piston through the exhaust port if the piston only had few scratches, not scored/scuffed/chewed on due to scrubbing on the cylinder wall I would then check the compression. If the piston is scored and scuffed due to rubbing on the cylinder wall no need in a compression test because the block has cancer and the engine is eating itself. It been hot and even after a repair with cylinder kit it may just ruin itself again if the cause is not investigated. (usually piston/block overheating is the cause of piston scuffing and happens when the saw is being used in a full bar or loaded heavy cut for more than 30 seconds) I've used a IR therometer with good results to monitor block temp to indicate if the saws block is overheating.
Usually requires a full bar loaded cut at full throttle for longer than 30 seconds to detect a chainsaw block to start overheating. Short cuts of less than 30 seconds in and out of a cut may not indicate any severe overheating and the saw may operate ok for quite awhile, but is just waiting for a overheat to occur when loaded up heavy in a full cut.
If your friend is not going to try repairing his own saw I would probably suggest to him to go get a new saw. (and quit using E10)
other option would be a 2nd opinion from another shop and not even mention the first shops opinion when going for the 2nd opinion.
