Stihl Ms391 Replacement Piston 49mm, Replaces Part # 1140 030 2003

Suitable, high quality replacement STIHL MS391 REPLACEMENT PISTON 49MM, REPLACES PART # 1140 030 2003 We sell all cylinders and pistons with the up-most confidence due to the following reasons: 1.Material- The factories use the highest grade material coming from Japan. This is AC4B. 2.Coating- Before coating, all are put through 13 preliminary processes to ensure maximum penetration, thickness and coverage. Coating thickness is .04-.06 mm of chrome which increases the life of the cylinder. 3.Machining- Complete machining on all cylinders is performed by accurate CNC tool machines. 4.Die-Casting- All cylinders are made by slow gravity fed die-casting. This increases the weight of the cylinder which enhances the performance and life of the rebuild. 5.Tooling- Each cylinder tooling has limited life and are replaced after the manufacturing of 50,000 pieces. All tooling is checked on a monthly basis. 6.Quality Control- Special inspection is done on every cylinder inlet and exhaust port which includes chamfering of all burrs. Every 20th cylinder that comes off of the production line in thoroughly inspected for accurate tolerances.  cylinders & pistons are manufactured by factories that have over 30 years of experience in the cylinder & piston industry. They provide OEM chainsaw suppliers (Western, European, & Chinese) as well as OEM for motorcycle companies. You can expect three times more life out of our cylinders & pistons than our cheaper competitors. Most of the cheap Chinese cylinders that we see look good, fit okay, but do not last because the don't go the extra length to ensure good quality. Note: We recommend when rebuilding 2-cycle equipment that you use a piston ring compressor kit to ensure professional results.