SCHEDULE 13D/A 0001641172-25-022637 0001517040 XXXXXXXX LIVE 22 Common Stock 09/18/2025 false 0001137091 73933G202 POWER SOLUTIONS INTERNATIONAL, INC.

201 Mittel Drive Wood Dale IL 60191

Gary S. Winemaster (630) 350-9400 2140 Kingfish Road Naples FL 34102 0001517040 N Gary S. Winemaster OO N X1 1454578.00 681.00 1454578.00 681.00 1455259.00 N 6.3 IN Common Stock POWER SOLUTIONS INTERNATIONAL, INC. 201 Mittel Drive Wood Dale IL 60191 Item 5(a) of this Schedule 13D is hereby amended and restated in its entirety as follows: The information contained on the cover pages is incorporated herein by reference. The Reporting Person may be deemed to beneficially own 1,455,259 shares of Common Stock, representing 6.3% of the Common Stock outstanding based upon 23,029,846 shares of the Issuer's Common Stock outstanding as of July 31, 2025, as disclosed in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on August 8, 2025. Item 5(b) of this Schedule 13D is hereby amended and restated in its entirety as follows: Number of shares the Reporting Person has: Sole power to vote or direct the vote: 1,454,578 Shared power to vote: 681 Sole power to dispose or direct the disposition of: 1,454,578 Shared power to dispose or direct the disposition of: 681 Since the most recent filing on Schedule 13D, the Reporting Person has not engaged in any transactions in the Issuer's Common Stock other than the following, each of which involved a series of open market transactions on the Nasdaq stock market: -- On August 7, 2025, the Reporting Person sold 2,594 shares of Common Stock at a weighted average price of $91.683 per share. -- On August 8, 2025, the Reporting Person sold 203,938 shares of Common Stock at a weighted average price of $107.7395 per share. -- On August 11, 2025, the Reporting Person sold 12,605 shares of Common Stock at a weighted average price of $104.2741 per share. -- On September 18, 2025, the Reporting Person sold 112,915 shares of Common Stock at a weighted average price of $105.8548 per share. -- On September 19, 2025, the Reporting Person sold 143,352 shares of Common Stock at a weighted average price of $109.4043 per share. None. Not applicable. Gary S. Winemaster /s/ Gary S. Winemaster 09/22/2025