A 50mm piston kit for the Stihl BR500, BR550, BR600 and BR700 4-MIX backpack blowers. The kit contains the piston with ring set, wrist pin and two circlips; gaskets, seals, valves and bearings are not included, so it suits an engine whose gaskets and seals are still good. It replaces piston kit 4282-030-2003. The BR800 family takes 4283-030-2003, which differs in the fourth digit and does not fit; nor does the kit fit the two-stroke BR340, BR380 and BR420. A scored piston on these blowers usually comes from an air leak at a hardened crankshaft seal or intake boot, a blocked fuel filter or the wrong fuel mix, so find and fix the cause before fitting the new piston. Use a ring compressor and set the valve clearance to the service manual figure after assembly.
- PISTON ONLY - A 50mm piston with ring set, wrist pin and two circlips. No gaskets, seals, valves or bearings: this is for an engine whose gaskets and seals are still good.
- FITS STIHL BR500, BR550, BR600 AND BR700 - The 4-MIX backpack blowers with the 50mm bore. Not for the BR800 family, which takes piston 4283-030-2003, or for two-stroke blowers such as the BR340, BR380 and BR420.
- REPLACES PISTON KIT 4282-030-2003 - Also written 4282 030 2003. The BR800 number, 4283-030-2003, differs in the fourth digit and does not fit, so check that digit on your parts list.
- WHY A PISTON FAILS - A scored piston on these blowers usually comes from an air leak at a hardened crankshaft seal or intake boot, a blocked fuel filter or the wrong fuel mix. Fix the cause first or the new piston goes the same way.
- BEFORE IT GOES TOGETHER - Find out why the old piston failed: an air leak at a hardened seal or intake boot, a blocked fuel filter or the wrong fuel mix will score a new one. Use a ring compressor and set the valve clearance to the service manual figure.