LAHDEK 40mm Cylinder Head Piston Kit For Robin FL411 NB411 NF411 5411500300

40 mm piston kit for Robin trimmers

This new cylinder-head and piston assembly replaces part 5411500300 on Robin FL411, NB411 and NF411 grass trimmers. It fits single-cylinder two-stroke petrol engines and includes the cylinder, piston, pin, ring and two circlips. The kit restores compression on worn or damaged top ends. Home owners and landscapers servicing these specific models will find it a direct fit.

40 mm cylinder bore defines fitment

The 40 mm bore diameter is the critical dimension that determines whether this kit matches your engine. Only trimmers built for a 40 mm cylinder accept these parts; other Robin models with different bore sizes cannot use them. Verify the original cylinder marking before ordering to avoid a mismatch.

Standard rebuild capacity for light-duty trimming

The assembly delivers factory-level displacement for routine grass and weed cutting on residential or light-commercial sites. It handles normal seasonal workloads without overheating when the fuel mix and cooling fins are maintained. Heavy brush clearing or continuous commercial duty may exceed the single-cylinder air-cooled design limits. Not for engines requiring larger bore sizes or four-stroke lubrication systems.