Primer Bulbs for Stihl FS / Zama Carburettors (12-pack, 19 and 22 mm)
Twelve replacement primer bulbs — six 22 mm and six 19 mm — listed for Stihl FS 38 to FS 130 trimmers and Zama carburettors. Fix a cracked or hard bulb.
In short:This COMVASTARS pack contains 12 clear plastic primer bulbs: six of 22 mm and six of 19 mm. They are listed for many Stihl machines, including the FS 38, FS 45, FS 55, FS 80, FS 85, FS 90, FS 100, FS 110 and FS 130, and for a long list of Zama carburettors. A split or hardened primer bulb stops the engine priming and starting. Measure your old bulb and check your carburettor model before ordering.
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Pros
- Two sizes in one pack — and spares for years
- Long list of Stihl models and Zama carb codes
- Fitted without tools on most carbs
Cons
- Pattern part — check size and model carefully
- Couldn't be dispatched to us in October 2026
What it is
A pack of 12 replacement primer bulbs from COMVASTARS: six 22 mm and six 19 mm, in clear plastic. The listing names many Stihl models — including the FS 38, FS 45, FS 46, FS 55, FS 75, FS 80, FS 85, FS 87, FS 90, FS 100, FS 110 and FS 130 — and a long list of Zama carburettor codes. When we checked in October 2026 it couldn’t be dispatched to our location.
Why bulbs fail
The primer bulb pulls fuel through the carburettor before a cold start. Sunlight, heat and ethanol fuel make it go hard, crack or split, and then it either won’t refill or sucks in air — so the engine won’t prime and won’t start. Our guide to a brush cutter that won’t start covers the other causes to rule out.
Fitting
On most Zama-carburetted Stihl trimmers, the bulb sits in a retainer on the carburettor: release the clip or retaining plate, pull out the old bulb and press in the new one of the same size. Measure the old one before choosing 19 or 22 mm, and check your carburettor code if you’re unsure. While you’re there, check the fuel lines for cracks — a fuel hose kit replaces those.
Related
Ethanol is the usual culprit for perished rubber and plastic parts — see ethanol petrol and brush cutters.
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