The Mercury Marine Mercury Seal 26-88397 is a water tube seal for use on various Mercury/Mariner outboard & Mercruiser stern drive engines.
 
Often referred to as the Race, Large, or Big Water Pump Tube found on all Speedmaster SSM #4 (IV),  Sportmaster, 2.5L Torquemaster Lower Units, big tube SSM #6 gearcases and Alpha One Gen 2 Sterndrives. The motors include 2.5 Liter EFI Offshore, 245 HP, 260 EFI, 280 ROS, 300 Drag, Mercury Racing S3000, S2000, SST-120, 200 XS, SST-200, Mercury 150 Pro Max, 200 Pro Max, 225 Pro Max, Mariner 150 Super Magnum, 200 Super Mag, and Mariner 225 HP Super Mag.
 
This seal fits on both sides of the water tube, (1) top (motor water exit exhaust plate), and (2) bottom (water pump housing), 
 
Mercury OEM Part Numbers
26-88397, 88397
 
Included one (1) Mercury Big Tube Water Tube Seal Grommet.
 
Contact mike@buckshotracing77.com or 714-697-1716 with any questions.