Can I save this piston? Stihl 026

[davidtown]

Purchased this saw used in decent condition. Pulled apart to clean and observed some lite scoring on the intake side. The marks on the intake side of the piston can be felt with a finger nail. No deep scoring on the cylinder and I feel I can clean that up.

What do you think?

Pictures are attached.

Be well,
Dave

 

[fossil]

Nice clean up job. I sure as heck wouldn't worry about running that

 

[cuinrearview]

Run it

 

[davidtown]

Thanks for the response and I can run the piston/cylinder once cleaned.
For conversation purpose and my own curiosity...cleaning up the scratches on the piston skirt won't change things negatively?

By the way the ring gap is .006 and .008.

Be well

 

[fossil]

Just sand off any high points on the scratches. Don't take it down to get them out.

 

[TheTone]

Just sand off any high points on the scratches. Don't take it down to get them out.

Ditto. And with those ring gap measurements, put them back in. Make sure the cylinder/skirt clearance is OK. Clean the grooves, and put the ring with the narrowest gap on top (assuming there are no nicks on them, which I don't see from the pictures).

 

[davidtown]

Perfect. Thank you all for the advice. I'll post up results

 

[davidtown]

Run it? I don't have measurements on the piston skirt to cylinder clearence. Nothing can be felt with the finger nail.

 

[Mad Professor]

You can check clearance with feeler gauges. at the bottom of skirt, ~0.002-0.0025 " is "new". Over 0.004" I'd think about a piston.

 

[motorhead99999]

I’d run it. Worst it can do is go bang. If your worries about it order a pop up piston for it.

 

[cuinrearview]

I'd go a little harder on that cylinder with some 500 or finer grit. Or just spin some red scotchbrite in there for a while.

 

[davidtown]

Thanks for the response and I will sand some more. Not worried about it going bang but enjoy the learning process.

Using the feeler gauge I can move the .003 and .004 feeler gauges but the .006 doesn't slide. The .006 will go in but doesn't move unless forced. Only going in a 1/4'' with the feeler gauge...here comes the "that's what she said jokes.

 

[davidtown]

Also, I have an aftermarket p/c from a previous project that is unused. Testing the aftermarket piston on my OEM cylinder the clearance is tighter than .003. I don't have a thinner feeler gauge.