56-2 Bump Feed Trimmer Head Why It Stops Feeding Line

Why does the trimmer head refuse to feed line when you bump it? The 56-2 head is a bump-feed unit: while the shaft is turning, a tap against the ground or grass pushes out a fresh length of line. When the line will not come out, it is almost always one of three things — the line broke inside, it wore down too short, or the feed mechanism jammed.

The head has a white top guard and a black base, with one line leading out of each side. The center thread is M14x1.5, so it screws straight onto the shaft of a matching trimmer with no adapter. Refitting is simple: cut the line to length, pass it through the two holes in the top cap, and tighten the nut.

When should the head itself be replaced? If the line feeds again after you re-thread it, the housing is still good. Replace the whole head when bumping no longer advances the line, the inside of the cap is worn down, or the base is cracked. Heads with a similar look, such as the 25-2, are close in design but not guaranteed to interchange, so check the thread and base shape against your old part first.

For yard owners, orchard crews or parts sellers, one spare 56-2 trimmer head on the shelf is worth keeping — it is the part that wears out first, and having it on hand saves the trip home.