X0407 4/A 2023-04-25 2023-04-26 0 0001137091 POWER SOLUTIONS INTERNATIONAL, INC. PSIX 0001852699 Xykis Constantine C/O 201 MITTEL DRIVE WOOD DALE IL 60191 0 1 0 0 See remarks 0 Stock Appreciation Rights 2.99 2023-04-25 4 A 0 85000 0.00 A 2023-04-25 Common Stock 85000 148505 D The Issuer granted the stock appreciation rights (the "SARs") on April 25, 2023, pursuant to a Stock Appreciation Rights Agreement dated April 25, 2023, under the Issuer's 2012 Incentive Compensation Plan, as amended and restated. The SARs vest and become exercisable in three equal installments on each of April 25, 2024, April 25, 2025, and April 25, 2026. This Form 4 is being amended to correct the total number of SARs owned by the Reporting Person, which was misreported as 147,005 total SARs and should have been reported as 148,505 total SARs. The total number of SARs owned by the Reporting Person has been inadvertently misreported by 1,500 since the Form 4 filed on March 25, 2021. Chief Executive Officer and Chief Technical Officer /s/ Constantine Xykis 2023-05-04