how to polish scratches in cylinder bore

[slimbo3006]

Ok so I finally got a Piston/Cyliner for my old Poulan 3400. It is from 3800. (I really wanted a 4000 or 3700, but the price and availability were right with the 3800).

So the piston on the 3800 looks fantastic. and the Cylinder looks really good too. The only marks on the cylinder are in the typical location of the side of the exhaust port on the chain side. you can feel them when you run your finger over them, but they are not quiet deep enough to catch your fingernail on.
What would be the best way to kind of clean these up a lil? lightly sand with a wet Emory cloth??


Side note. So the 3400 P/C that I removed had pretty low compression. 120 cold and only 90 hot.. Saw did not pull very well at all. when I removed it, the piston and cylinder have transfer marks on the skirt below the intake port.. What would cause this? Otherwise neither really looked terrible.

Thanks

 

[J D]

I find a strip of scotch pad wrapped around a bit in a drill or rotary tool with some cutting/polishing compound works well. Intake side damage is usually lack of oil or ingestion of crap as far as I'm aware... Web search for 2 stroke piston damage cause should provide some useful charts

 

[Andyshine77]

You nerd to go over to the Nik's Poulan thread in the sticky section!https://r.tapatalk.com/shareLink/to...&share_fid=16367&share_type=t&link_source=app

I know the 3400 has an uncoated bore, the piston is chrome plated, not sure about the 3800,but the 4000 will have a plated bore. So you need to be real careful with the unplated cylinder, I believe you just smoothe them out a little, no sanding.

 

[Ted Jenkins]

You nerd to go over to the Nik's Poulan thread in the sticky section!https://r.tapatalk.com/shareLink/to...&share_fid=16367&share_type=t&link_source=app

I know the 3400 has an uncoated bore, the piston is chrome plated, not sure about the 3800,but the 4000 will have a plated bore. So you need to be real careful with the unplated cylinder, I believe you just smoothe them out a little, no sanding.

Yes that is correct do not spend too much time sanding it as you will possibly damage cylinder. A scratch that does not protrude will cause no harm. Under some conditions it will carbon up and not be noticeable. Thanks

 

[slimbo3006]

good deal. thanks for the info. Yea the bore is not coated..that is why I was a lil hesitant to do much work on it.
I'll check out the poulan thread