I'm working on a few saws for some of the guys around here. I run into all kinds of issues as most of these saws are rode hard and put away wet... Jonsered 2065 turbo with broken chain tensioner is getting a MM and base gasket delete if squish can handle it. MS291 with trashed piston, bad carb, broken off oiler bolt due to a bearing failure, oiler is trashed too. MS391 with a bunch stuff, but the cylinder was losing plating. I can't locate an aftermarket cylinder with the same intake configuration to it's just getting put back together and is pretty much just a parts saw now but he'll probably run it till it destroys itself. Easy out to the rescue... bearings off... bearings on... I picked up a couple more big duffle bag style luggage pieces at a local thrift store I can use for rope bags... 5 bucks for both of them. Zippers all work. I have a couple of 200' bull ropes that I didn't have bags for. I like keeping all the ropes in bags so I'm not always un-tangling them.
ProlineĀ® Cylinder Piston Kit For Stihl MS311 MS391 49mm 1140 020 1204 Nikasil They made three styles so not sure if this is it.
Now look at what its inside looks like. These were taken an hour after the video. This thing starts in 1-3 pulls and I've ran 1/2 gallon or more of mix through it like this.
I used some acid to remove the aluminum transfer and found the plating damaged. Those white spots. I'm going to unstick the ring, smooth out the pits, clean the exhaust port out and run it. I only use it for sweeping the garage and light stuff. I have almost nothing into it. I got it, another blower and a trimmer for $3.50. This blower and the trimmer run.
I've never used acid to remove the aluminum transfer, but noticed a lot of folks use that method. I've always used a flap disc on drill to clean the cylinder up. Took a 1/4 piece of round stock, cut a slit and added a strip of sandpaper and went to town.
I saw a YT video of that Monkey feller down in Tennessee (Mastermind) and it's worked for me. I wound up making a fixture?, Tool for use with the Foredom. Looking forward to seeing it back up and running.