SEI has engineered replacement lower units for Mercury, Yamaha and Johnson Evinrude. The lower units offered by SEI are fully compatible and interchangeable with Mercury, Yamaha and Johnson Evinrude lower units.

SEI is currently producing lower units for V6 outboards. SEI’s lower units replace most V6 outboards from 1980 to present.

Often SEI is asked about the quality of our lower units and how the company is able to offer such a product at a fraction of the OEM price. SEI's Lower units are assembled at our factory in Clearwater, Florida. The parts come directly from suppliers around the world made to SEI's exact and precise specifications. Eliminating the middleman reduces SEI's costs and these savings are passed on to the customer. SEI also avoids using distributors thus reduces the company's costs at getting the product into the hands of the boat owner. As for quality, SEI's Lower units are thoroughly tested for both performance and endurance. SEI operates one of the world's only research lakes dedicated to the testing of marine propulsion systems.

SEI's Lower units come with a three-year, fault-free warranty which means that the lower unit will be covered for any failure that requires the lower unit to be replaced or repaired. This is truly a remarkable warranty. Hit a rock, suck up some fishing line, drag the lower unit up the boat launch by mistake, it does not matter, the lower unit will be covered by SEI's fault-free warranty.

SEI has been in the stern drive business since 2003. The company was founded by Greg Pickren. Mr. Pickren also is the owner and founder of the company Short Block Technologies (SBT) which is the largest supplier of Personal Water Craft engines in the world. Justin Webb is the General Manager of SEI and was previously employed by Konrad Marine and GLM.

SEI is also working on producing lower units for smaller 3 and 4 cylinder Mercury, Yamaha and Johnson Evinrude Outboards.