10 Pack Carburetor Primer Bulb for Stihl FS55 FS55R FS56RC FS70 FS80R FS85 FS90 FS90R FS91 FS91R FS110 FS111 FS130R FS40C FS45 BG55 BG56C BG65 BG75 BG85 BG86 0057003 0057004 String Trimmer

What It Is

This is a 10-pack of aftermarket primer bulbs designed for Stihl handheld equipment—trimmers, blowers, and brushcutters. The bulb manually pumps fuel into the carburetor to prime the engine for cold starts.

Fitment & Compatibility

Check your machine’s model number against the list: FS55, FS55R, FS56RC, FS70, FS80R, FS85, FS90, FS90R, FS91, FS91R, FS110, FS111, FS130R, FS40C, FS45, BG55, BG56C, BG65, BG75, BG85, BG86. These bulbs match Stihl OEM part numbers 0057003 and 0057004. Before buying, measure your old bulb’s diameter (typically ~15mm) and stem length—aftermarket bulbs can vary slightly. Confirm your carburetor uses a push-in style bulb (not threaded or screw-in). If your machine uses a different primer system (e.g., bulb integrated into the fuel tank), this won’t fit.

Key Things to Know

• Quality variance: Aftermarket bulbs may be slightly softer or stiffer than OEM. The 10-pack allows for trial-and-error or future replacements.
• Installation difficulty: Easy—pop off the old bulb, clean the recess, and press in the new one. No tools required, but ensure the bulb seats fully to avoid air leaks.
• Common gotcha: If the bulb doesn’t spring back after pressing, the check valve in the carburetor may be clogged—replacing the bulb alone won’t fix that.
• Not for all Stihl models: Double-check your model number; some newer Stihl trimmers use a different bulb design (e.g., FS 94 R).

Should You Buy It

If you own multiple compatible Stihl units or want spares on hand for future repairs, this 10-pack is a cost-effective buy at ~$0.60 per bulb. It’s a solid choice for DIY repairs where OEM pricing isn’t justified, but expect slight fit/feel differences from factory parts.