A 50mm piston kit for the Stihl BR800, BR800C, BR800X and BR800C-E 4-MIX backpack blowers. The kit contains the piston with ring set, wrist pin and two circlips; gaskets, seals and valves are not included. It replaces piston kit 4283-030-2003. The BR500, BR550, BR600 and BR700 take 4282-030-2003, which differs in the fourth digit and does not fit, so read the model on the frame plate before ordering. The piston has a raised dome, giving a higher compression ratio than a flat-top piston, so check piston-to-head clearance before running the engine. A scored piston on these blowers usually comes from dust past the air filter, an air leak at a crankshaft seal or the intake, or the wrong fuel mix; find and fix the cause, pressure and vacuum test the crankcase, use a ring compressor, and set the valve clearance after assembly.
- PISTON KIT - A 50mm piston with ring set, wrist pin and two circlips. Gaskets, seals and valves are not included.
- FITS STIHL BR800, BR800C, BR800X AND BR800C-E - The 4-MIX backpack blowers with the 50mm bore. Not for the BR500, BR550, BR600 and BR700, which take piston 4282-030-2003, so read the model on the frame plate.
- REPLACES PISTON KIT 4283-030-2003 - Also written 4283 030 2003. The BR500 family number, 4282-030-2003, differs in the fourth digit and does not fit, so check that digit on your parts list.
- DOMED TOP - The piston has a raised dome, which gives a higher compression ratio than a flat-top piston. Check piston-to-head clearance before running the engine.
- BEFORE IT GOES TOGETHER - Find out why the old piston failed: dust past the air filter, an air leak at a crankshaft seal or the intake, or the wrong fuel mix will score a new one. Pressure and vacuum test the crankcase, use a ring compressor, and set the valve clearance to the service manual figure.