Sachs Piston Skirt Repair

[spowell]

I was reassembling my 125cc Sachs when I noticed a horizontal crack in the skirt of the piston. It is about 1/4" long and about 2mm up from the edge of the skirt on the intake side. Can I mill out the damage and continue to use the piston? It would affect the intake timing slightly, would the engine still idle?

I tried to include a photo but was not successful.

[G Ellis]

I would not use it. Better off putting a new piston in.

[Paul Danik]

Possibly to much piston to wall clearance could cause the piston to do what is referred to as "slapping", the slapping of the piston skirt against the cylinder wall can cause the skirt to crack. Would suggest careful measuring of the piston clearance, possibly an oversized piston and a bore job are needed.

Good luck.

Paul

[Todd Rovello]

Paul, I am about to have a 6B engine bored 1 size over. Is it recommended to machine the head to match, or is it not necessary when boring just one size over?

Todd Rovello

[spowell]

I think it happened during disassembly, it looks like the edge was dented and that caused the crack. I will try the new piston approach. Thanks.

[Paul Danik]

Todd, the head should be fine as is.

Paul

[Todd Rovello]

Thanks Paul,

Todd

[gooddirt]

you can rise the intake timing to the 2mm on the piston intake and should run fine