HONDA GX31 UMK431 139F 39mm Piston Kit

39mm piston kit fits Honda GX31 and UMK431 engines (139F 39mm platform), designed to restore proper engine compression and reliable power output. This kit includes a 39mm piston, piston rings, wrist pin and circlips, ensuring smooth piston movement, consistent combustion and optimal engine performance. A practical replacement for worn or damaged piston components on compatible petrol garden tools such as strimmers and brushcutters, helping maintain stable operation and extend engine life.

Fits specified Honda engines:

Honda GX31

Honda UMK431

Replaces part number:

• 13101-ZM5-000