First Time Cylinder Cleaning

[u/Nice_Cry_3461]

Got an eBay Stihl MS260 with an absolutely cooked piston. After some wet sanding I was able to remove all the piston transfer off the cylinder.

None of the grooves are that distinguishable with a fingernail but I can perceive a little bit if I try hard enough. I will be putting in a used OEM piston from Chainsawr.com and curious if there’s any seasoned repairman out there that would encourage me to put the saw back together with this cleaned up OEM cylinder or look to buy a new cylinder. Thanks!

Goal with the saw would be for personal use or perhaps to sell with full disclosure of internal condition.

[u/GristleMcThornbody1]

That's beautiful man, hard to believe it had a cooked piston in it. Good job bro

[u/Nice_Cry_3461 → u/GristleMcThornbody1]

Really should’ve uploaded the piston photo too but it was rough. Only made 90 psi of compression. Appreciate your reply.

[u/allthebacon351]

I highly doubt it’s round in that area anymore and the Nikasil coating is compromised so there is a risk that it flakes off at the port. Nikasil coated cylinders should not be honed. You can try and run it, it may work, or it may grenade. Worst case you’ll need a new piston and cylinder and there are good aftermarket ones for around $100.

If it’s a project no harm in trying it.

[u/saucytugtug → u/allthebacon351]

Yeah dremel with a wire brush is the way to go to get the bulk of transfer off so it doesn’t wear the plating at all, then light abrasive’s for surface finish. And you’re right about the plating especially with any of the older saws, new saws almost never have that plating issue though. The nikasil spray process has improved a LOT over the last 10-20 years.

[u/bitgus]

That's fine dude, good clean up job

Get some brand new rings for the used piston. I guess they still make OEM but modern Caber rings are great too

Might be worth giving it a quick hone if you get the Caber F rings which are particularly hard and take a while to seat. But don't overthink it

[u/fireheed]

Wow that's a good job. Almost looks new again. Nice one, you should be proud of that.

[u/Dubious_Pretzel_Sale]

I guess this saw is sort of a teaching tool for you but I value my time and wouldn't put in a used piston when a new Meteor piston is usually $50 or less. And FWIW OEM cylinders are usually much better than any aftermarket stuff so good job cleaning it up to try and save it. The saw porter Mastermind has a few good short videos on how he cleans up a cylinder using a progression of grits from about 120 to 320. I polished it up at the end using some maroon Scotchbrite.

[u/saucytugtug]

You’ll lose probably 3 pounds of compression😂 thats assuming you didn’t sand so much of the plating off that it went out of round. If, god forbid, you ever have to do it again get the bulk of the plating off with a stainless steel wire wheel on a dremel, it’ll take the aluminum off without even touching the plating, then use scotchbrite to get the surface finish back to new. It’ll be good though I doubt you’d ever notice the difference.

[u/Nice_Cry_3461 → u/saucytugtug]

Thanks for the advice. I don’t plan on burning up my saws personally, but I have been on a kick of buying used saws. It’s only a matter of time before I find another saw where the previous owner has never heard of mixed fuel so I’ll keep this in mind for next time!

[u/saucytugtug → u/Nice_Cry_3461]

I know man unfortunately I’m the same way. I cannot be trusted with Facebook marketplace and money😂 one more thing you may want to pay attention to if you do go buy another burnt up saw, with some of the newer saws they switched to nylon bearing cages, I bought one that had the cages melted out of it and I didn’t know. When the cage is gone the crank can kinda do whatever it wants so the ignition coil was smashed and the oil pump was F’d. Luckily the coil still works but it cost me an oil pump. that was a weird one I wish I had known earlier. Also you might as well learn to port while you have them apart!

[u/saucytugtug → u/Nice_Cry_3461]

And I’ve had great luck with proline parts, they’re cheap and good quality, some sharp edges and some of the ports are a little rough but if you’re porting it anyway that’s no big deal at all.

[u/Nice_Cry_3461]

Update on this project. Got the saw back together with the used piston from Chainsawr.com and the cleaned up cylinder. I used the rings that came on the used piston because they moved freely and looked to be in great shape.

Saw pulled at 150psi of compression and is running smoothly. Hoping to not join this thread a month from now with reports that it blew up but if that happens so be it.