The Mercury Racing Short-Ram Trim Cylinder Repair Kit (Part Numbers 211163 and 25-11163A 1) is built to restore trim cylinders used on high-performance Mercury Racing outboards. Trim cylinders control engine angle, which affects holeshot, cornering, and top speed. Under heavy use, seals and gaskets wear down, leading to leaks and weak hydraulic response. This kit replaces those components with new OEM parts to return cylinders to factory condition.
What's in the Kit?
Each kit includes precision-matched seals, O-rings, and gaskets. Replacing them restores hydraulic sealing, eliminates leaks, and ensures trim systems operate smoothly under load. For technicians, this means accurate rebuilds with fewer comebacks. For racers, it means consistent performance and reliable trim response in competition.
Applications and Motor Fit
The kit is used across Mercury Racing’s modern APX series—including the 3.4L V6 200 APX, 4.6L 250 APX, and 360 APX with 12-inch mid-sections—where trim control is vital for competitive handling and speed.
It also supports legacy engines such as the 2.5L EFI/ROS, 300 Drag (15"), SST-120, SST-140, S3000, F1, SST-200, and 200XS (12"). These outboards remain staples in high-performance boating, from vintage drag races to modern tunnel-hull competition.
Racing Use Cases
In outboard drag boats, quick trim adjustment can determine the winner at launch. In F1H2O international races, tunnel hulls demand flawless hydraulic systems to maintain stability at extreme speeds. The kit is equally critical in USF1 circuits and SST-120 classes, where precise trim settings protect both performance and safety.
Installation Tips
When installing, technicians should inspect the ram shaft for corrosion or scoring, since seals cannot compensate for damaged surfaces. All hydraulic fluid and debris should be flushed before reassembly. Seals should be lubricated with Mercury Racing hydraulic fluid to seat correctly.
The trim cap should be removed with a properly fitting pin wrench, slowly and with care to avoid galling or damage. Fasteners must be torqued to factory spec to avoid distortion, and once complete, the system should be cycled under load to confirm smooth, leak-free operation.
A properly rebuilt trim cylinder allows for precise engine angle adjustments, sharper holeshots, more stable cornering, and reliable top-end speed. Whether running an outboard drag boat, F1H2O, USF1, or SST-120 in competition, the Mercury Racing Short-Ram Trim Cylinder Repair Kit (211163 / 25-11163A 1) ensures that trim systems deliver race-ready precision every time.
For technical support, contact Mike Hill at +1-714-697-1716 or mike@buckshotracing77.com