Primer Bulbs

Primer bulbs and fuel primer assemblies for chainsaws, trimmers, brushcutters and blowers, fitting brands including Stihl, Ryobi and McCulloch. The primer bulb pumps fuel through to the carburettor before you pull the starter cord, which makes starting easier, especially when the engine is cold.

A primer bulb that's gone hard, cracked or won't hold its shape after pumping is a common reason a machine becomes hard to start. Bulbs and assemblies are listed by model and by outside diameter (such as 22mm OD), and are available as single units or in packs of 2, 5 or 10 for those who service multiple machines.

Frequently asked questions

What does a primer bulb actually do?

It pumps fuel from the tank into the carburettor before starting, which helps the engine fire up more easily, particularly from cold.

How do I know if my primer bulb needs replacing?

If the bulb feels hard, is cracked, or doesn't spring back after you press it, it's likely no longer sealing properly and should be replaced.

Do I need the exact model match or just the right size?

Where possible match by model, but if you can't find your exact model, checking the outside diameter (such as 22mm OD) against your old bulb is a reliable way to get the right fit.