Compatible with Stihl Ms661 56mm Pop Up Piston Kit Extra Power High Compression Replaces Part# 1144-030-2001

Compatible with Stihl Replacement Pop Up Piston Assembly, Replaces Part Number 1144-030-2001, Quality Reproduction For Model MS661 Piston Is 56mm In Diameter. This Piston Will Give You Extra Compression And Extra Power.

• MEASURE THE BORE BEFORE ORDERING - A caliper across the old piston crown settles which version of the engine you have, and it is the only test that does. Ordering by horsepower or by year is how the wrong part ends up on the bench, because the same machine was often built in more than one bore. The number this replaces is 1144-030-2001.
• CHECK RING END GAP IN THIS CYLINDER - Not in the old one. Square the ring in the bore, measure the gap with a feeler, and check side clearance in the piston groove while you are there. A ring that is tight at operating temperature will break a land.
• WORK OUT WHY THE OLD ONE FAILED - A scored bore had a cause. A hardened crankshaft seal or a split impulse line leans the mixture out and will take the new piston the same way it took the old one. Pressure and vacuum test the crankcase before the machine goes back together.
• ON ASSEMBLY - Use a ring compressor, fit the circlips with the open end away from the ports, and hone the bore so the rings have a surface to bed into. Turn the engine over by hand before the first start.