Should this piston be replaced?

[Ryan625]

Is there any prep work I should be doing to the cylinder before reassembly? I've read conflicting things about rehoning, not sure if the cylinder has glazing some of the crosshatching is still visible. 

[peatff]

I just rub them round with some 240 and WD or 2 stroke oil, never used a hone on them.

[openspaceman]

1 hour ago, peatff said:

I just rub them round with some 240 and WD or 2 stroke oil, never used a hone on them.

Nor me as I don't have one but as you say wet and dry round the circumference of the bore not up and down. The idea being the scratch marks retain a bit of the oil.

[Aled Hughes]

On 22/07/2024 at 10:38, openspaceman said:

Nor me as I don't have one but as you say wet and dry round the circumference of the bore not up and down. The idea being the scratch marks retain a bit of the oil.

Tell you what I've found useful is a sanding flap wheel, slightly larger as the flaps will flex into the bore size and it works a treat.

[openspaceman]

Well I hope you go gently with it, New nikasil is only 20 thou thick.

[spudulike]

I reckon Nikasil plating must be well under 20 thou - around 5 thou I would reckon and personally, I usually use a three legged hone very lightly, it always worked well for me. The art is to get a bit of roughening of the bore without taking much off and not catching the ports with the legs.

 

[adw]

I hate to sound like a well worn record but Flex hones I have used for years, maybe too expensive to do just one cylinder, but they are really good.

[peatff]

13 hours ago, openspaceman said:

Well I hope you go gently with it, New nikasil is only 20 thou thick.

 

Average thickness new is .005", 20 would be generous.

[Ryan625]

Saws running well, carb just needs a rebuild and it should be good to go. However I've encountered an issue with my fuel mix, I've mixed it at a 50:1 ratio but it's smoking like mad when cutting. I'm thinking the mix is oil rich or it's low quality oil?? Rocwood brand 

[Ryan625]

And is it necessary to recalibrate the autotune after rebuilding a saw? (Husqvarna 545)