Sterndrive Engineering (SEI) is the largest supplier of aftermarket sterndrives and our own line of outboards in the world. The company makes replacement sterndrives for MerCruiser's® Alpha One® and Gen II stern drives and replacement outboard lower units for Mercury®, Johnson/Evinrude® and Yamaha®. Sterndrive Engineering's Outdrives are not remanufactured, they are entirely new. The SEI drives are made of parts that are completely compatible and interchangeable with the OEM. The drives are assembled at SEI's factory in Oldsmar, Florida.

SEI's drives come standard with a three-year, fault-free warranty. This means that the unit is covered for any failure that requires the drive to be repaired or replaced. Run it without lubrication, crash into a stump, suck up some fishing line, it does not matter, the SEI drive is always covered. SEI believes this warranty is one of the best warranties ever offered for a stern drive or a outboard lower unit. Peace of mind while on the water is important, and SEI goes the extra distance to make sure that our products perform.

SEI has done extensive testing on all of the parts of the drives including the gears, shafts, bearings, and other wear parts to confirm performance and durability. SEI operates one of the only research lakes in the world dedicated to the testing of marine propulsion systems. The research center has a 40-acre lake with a stationary dock that allows for around-the-clock endurance testing of parts, such as gears, shafts, and bearings.

SEI has the best prices by far for replacement drives compatible with MerCruiser's® Alpha One®, Gen II, Mercury®, Johnson/Evinrude® and Yamaha®. Often the company is asked 'How do we do it?'. SEI buys its parts directly from manufacturers and passes the savings on to the customer. The marine industry is notorious for multiple layers of distribution which adds cost to the end user. By avoiding the middleman, SEI is able to offer a quality drives at a fraction of the price offered by others.

SEI also offers a complete line of hydraulic parts compatible with MerCruiser® Sterndrives. The products offered include hydraulic pumps, trim cylinders, hoses, fittings, and other accessories. SEI also offers a gimble housing repair kit.

SEI's mission is to make owning, operating, and maintaining a sterndrive or outboard lower unit more affordable. Thanks for your interest in SEI.