Cleaning Up Scored Cylinder???

[seagiant]

Hi,
Bought a burnt up almost new ECHO CS-590 and trying to get opinions on the Cylinder.

I have not tried to save a scored cylinder before but would help money wise if I could.

Here are some pics, what do you guys think, AND...

What is the best method to get the scratches out???

 

[Mad Professor]

Most of that is aluminum transfer. Gently take that off to see how the plating is underneath.

It may clean up , it might not. How does piston look?

 

[seagiant]

Hi,
Here is the piston!

 

[seagiant]

Hi,
Well, took some wet/dry 400 grit and gave it a go, and...

Does not look that bad?

Might just get a Piston Set and see what it does?

Thanks to "9050lx", for wising me up!

 

[Mad Professor]

I still see a little of what looks like transfer, but looks much better.

Wet/dry with some dish detergent. Rinse then with a q-tip apply muriatic/hydrochloric acid to just the transfer, avoid the port chamfers and any obvious planting defects. Have some baking soda solution to rinse with and take care of any spills/mistakes. Repeat until you no longer see transfer dissolved.

Might go to 320 at first.

 

[Vintage Engine Repairs]

Looks much better, but you’ve still got a long way to go, as above, 320, or better yet, maroon scotch brite and lots of elbow grease.

 

[seagiant]

Hi,
Thanks, will have to stop at ACE Hardware tomorrow, I guess!

 

[muddstopper]

I usually split a dowel rod on one end and chuck in my drill. I then put scotchbrite in the split dowel and use the drill to polish the bore. Spray a little pb nutblaster on the scotchbrite and let it rip. Lot safer than the acid and will leave the bore polished shiny. Then replace the scotchbright with a piece of 360 grit emory cloth and hit the cyl again, just enough to leave a nice cross hatch pattern.

 

[seagiant]

Hi,
Thanks, I'm gonna pass on the Acid.

I think with some scrubbing I can get it acceptable, but need some things!

Ordered a OEM ECHO Piston Kit!

 

[9050LX]

Final question is why?Straight gassed?

 

[seagiant]

Hi,
Must of been.

I bought it after the accident, but looks brand new?

 

[9050LX]

The piston in my Echo looked a lot like yours.Still no idea what happened.That carburetor likes to run rich at any high needle setting, so probably straight gassed.I checked for leaks,changed out the seals, ended up using the check valve that doesn't bypass extra fuel to the main circuit so I could lean it out a bit.Took several hours to finally break in, I feel, on this saw with the LRB piston.Runs very strong.

 

[seagiant]

Hi,
Any 2-stroke motor that I get...

I pull the limiting caps off if I can.

For others, I have the screwdriver set, with all the different heads.

I have to be able to adjust the carb or it bugs me.

Weather, this Saw was run with straight gas, or the carb set to lean, I don't know?

 

[Vintage Engine Repairs]

Hi,
Must of been.

I bought it after the accident, but looks brand new?

Don’t guess on this one, make sure you find the cause, or at least check everything to make sure that it could only be straight gassed.

 

[Patrick1903]

I have a similar thread I started a couple days ago on my ms391 top end project, but not gaining any traction on opinions from many folks. I had originally just bought a new piston and cylinder kit but then it was suggested that I may as well see if I could get the cylinder cleaned up. I couldn’t come up with a good split mandrel for sandpaper or emery cloth with my hand drill, so I started with green scotch brite. It cleaned up ok, but not good enough. There were still raised aluminum pieces I could pull off with a pointed object. Then I came up with a mandrel by removing the handle from a tire plugger thing… not the rasp but the one to drive in the plug. It has an open end for the tire plug, and the other end that used to have a plastic handle is now just the other end for my drill. I doubled a strip of emery cloth over (200 grit) and worked at it.

Didn’t try pb blaster or oil. Just dry. Do people use polishing compounds? Not sure if it is clean enough. So do I try to get away with $50 for piston or just buy the kit for $120 for p&c. I’m afraid I’d go the cheaper route, then bc my cylinder isn’t polished well enough, chew up the cylinder and then have to go the more expensive route anyway, and will have spent more money with the cheap route! Turns out the p&c kit arrived with a nick in the cylinder, not sure if it would affect anything, but will try to exchange it. Just a bummer to take a week or so loss on shipping.

@seagiant let me know how the piston only route goes. If possible try to get some good pics of your polished cylinder so I can compare to my results.

And if anyone has any interest in my ms391 top end project, feel free to drop some advice there.
https://www.arboristsite.com/threads/ms391-top-end-rebuild-project.359708/

 

[seagiant]

Hi,
Well, at the end of the day, you do not want, "polished", you want to finish with a 320 grit from what I'm seeing.

Some people even use a Flex-Hone, to finish with (same grit) but that is money, too.

For my Cylinder, I think if I get some 320 wet/dry, and scratch pad, I can get mine back in shape...

No doubt, each cylinder depends, on the damage done!

 

[Vintage Engine Repairs]

320grit paper or scotch brite. Don’t stop until all transfer has gone for reference, expect over an hour of elbow grease. Maybe twice that. Put a good programme on and pour yourself your beverage of choice and get scrubbing.

 

[seagiant]

Hi,
Saw this, but hones aren't cheap and probably not practical for one use.

 

[Vintage Engine Repairs]

Hi,
Saw this, but hones aren't cheap and probably not practical for one use.

Don’t try and hone away transfer, you’ll worsen your problem destroying the hone in the process . This video was demonstrating removing the glazing from a cylinder, not transfer

 

[seagiant]

Don’t try and hone away transfer, you’ll worsen your problem destroying the hone in the process . This video was demonstrating removing the glazing from a cylinder, not transfer

Hi,
Yes, I picked that up, but would use one if I had one for final finish...

Too expensive, for no more than I would use it, and...

Of course, need different sizes for different cylinders! ($$$)