Echo CS-510 CS-520 CS-530 Two Ring Piston Kit 45mm P021006153

Two ring piston kit for the Echo CS-510, CS-520 and CS-530 chainsaws, 45mm bore. Replaces Echo part number P021006153. All three saws share the same 45mm bore, so one kit covers the family. CONTENTS. Piston, two compression rings, wrist pin and circlips. The cylinder is not included. Cylinder base gasket, exhaust gasket and crankshaft seals are not included and all are worth replacing while the engine is open. A COUNT YOU CAN RUN IN A SECOND. This piston carries two compression rings. Count the rings on the piston you remove. If it has one ring, you have a different Echo engine and this is not the part for it. BEFORE REASSEMBLY. A scored bore is a symptom. On these saws the cause is usually a lean mixture from a hardened crankshaft seal, a split or perished impulse line, or an intake boot that has gone loose or cracked. Pressure and vacuum test the crankcase and fix what you find before the new piston goes in, because the new one will fail the same way the old one did. ON ASSEMBLY. Check ring end gap in the cylinder the rings will run in, and side clearance in the piston grooves. Hone the bore lightly. Use a ring compressor, fit the circlips with the open end away from the ports, and turn the engine over by hand before the first start.

• 45MM TWO RING PISTON KIT FOR THE ECHO CS-510, CS-520 AND CS-530 - Piston, two compression rings, wrist pin and circlips, replacing Echo part number P021006153. All three of these saws share the 45mm bore, which is why one kit covers them. This is the repair for a saw down on compression, or one that has scored its bore running lean.
• WHAT IS IN THE BOX, AND WHAT IS NOT - Piston, two rings, wrist pin and circlips. The cylinder is NOT included, so this is for an engine whose bore is still good. Cylinder base and exhaust gaskets and the crankshaft seals are not included either. If the bore is scored or the plating has gone, the cylinder has to be replaced too and a piston on its own will not solve it.
• TWO RINGS, NOT ONE - This piston carries two compression rings. Count the rings on the piston you take out: if yours has one, you are looking at a different Echo engine and this is the wrong page. That single check takes a second with the old piston in your hand and it settles the question.
• FIND THE AIR LEAK BEFORE THE NEW PISTON GOES IN - A scored bore on these saws is nearly always a lean mixture, and the usual culprits are a hardened crankshaft seal, a split impulse line or a loose intake boot. Pressure and vacuum test the crankcase first. Fitting a new piston without finding the leak means doing this job twice.
• ON ASSEMBLY - Check ring end gap in this cylinder rather than the old one, and side clearance in the piston grooves. Hone the bore so the rings have a surface to bed into. Use a ring compressor, fit the circlips with the open end away from the ports, turn the engine over by hand before starting, and run the first tank a little rich while the rings seat.