Castle Nut 90171-16011-00

Taiwan-made brass slotted prop nut built to replace Yamaha 90171-16011, with a comparable hex profile, thread cut, and six castellations. Finish and machining look consistent, but it is not OEM-sourced and comes from a different factory than Yamaha.

RECmar China-made castle nut cross-referenced to Yamaha 90171-16011, with well-defined castellations and clean threads in the photos. Likely a workable replacement, but not an exact OEM match and long-term material consistency is less certain than Yamaha.

Parsun genuine part made in China; visually it has uniform slot spacing and clean internal threads similar to the OEM nut. It’s a functional substitute, but the different sourcing provides less assurance on alloy spec and tolerance control than the Japan-made Yamaha part.

Taiwan-made castle nut that matches the basic geometry and threading, but the slotted face shows a rougher machining texture and there are no manufacturer markings on the part. It should function, though QC and material traceability are less clear than OEM or branded aftermarket options.

We are working hard to determine a rating based on all available information, including product and manufacturing specifications.