Amendment: SEC Form 10-K/A filed by Power Solutions International Inc.

FORWARD-LOOKING STATEMENTS

Certain statements contained in this Amendment that are not historical facts are intended to constitute “forward-looking statements” entitled to the safe-harbor provisions of Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). These statements may involve risks and uncertainties. These statements often include words such as “anticipate,” “believe,” “budgeted,” “contemplate,” “estimate,” “expect,” “forecast,” “guidance,” “may,” “outlook,” “plan,” “projection,” “should,” “target,” “will,” “would” or similar expressions, but these words are not the exclusive means for identifying such statements. These forward-looking statements include statements subject to a number of risks, uncertainties and assumptions that may cause actual results, performance or achievements to differ materially from those expressed in, or implied by, such statements.

The Company cautions that the risks, uncertainties and other factors that could cause its actual results to differ materially from those expressed in, or implied by, the forward-looking statements include, without limitation; the factors discussed in Item 1A. Risk Factors in the Original 10-K; the impact of the macro-economic environment in both the U.S. and internationally on our business and expectations regarding growth of the industry; uncertainties arising from global events (including the Russia-Ukraine, Israel-Hamas and the U.S./Israel-Iran conflicts), natural disasters or pandemics, and their impact on material prices; the effects of strategic investments on our operations, including our efforts to expand our global market share and actions taken to increase sales growth; the ability to develop and successfully launch new products; labor costs and other employment-related costs; loss of suppliers and disruptions in the supply of raw materials; the Company’s ability to continue as a going concern; the Company’s ability to raise additional capital when needed and its liquidity; uncertainties around the Company’s ability to meet funding conditions under its financing arrangements and access to capital thereunder; the potential acceleration of the maturity at any time of the loans under the Company’s uncommitted revolving credit agreement through the exercise by any lender of its demand right in its Revolving Credit Agreement; the impact of rising interest rates; changes in economic conditions, including inflationary trends in the price of raw materials; our reliance on information technology and the associated risk involving potential security lapses and/or cyber-attacks; the ability of the Company to accurately forecast sales, and the extent to which sales result in recorded revenues; changes in customer demand for the Company’s products; volatility in oil and gas prices; the impact of U.S. tariffs on imports and exports; the impact of supply chain interruptions and raw material shortages, including compliance disruptions such as the Uyghur Forced Labor Prevention Act (the “UFLPA”) delaying goods from China; the potential impact of higher warranty costs and the Company’s ability to mitigate such costs; any delays and challenges in recruiting and retaining key employees consistent with the Company’s plans; the potential effects of damage to our reputation or other adverse consequences if our employees, suppliers, sub-suppliers or other contract parties, agents or business partners violate anti-bribery, competition, export and import, trade sanctions, data privacy, environmental, human rights or other laws; and the impact of unanticipated changes in our effective tax rate, the adoption of new tax legislation or exposure to additional income tax liabilities.

The Company’s forward-looking statements are presented as of the date hereof. Except as required by law, the Company expressly disclaims any intention or obligation to revise or update any forward-looking statements, whether as a result of new information, future events or otherwise.

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Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

SECURITY OWNERSHIP OF

CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth information known to the Company regarding beneficial ownership of shares of the Company’s Common Stock as of April 23, 2026, by:

The amounts and percentages of shares beneficially owned are reported on the basis of regulations of the SEC governing the determination of beneficial ownership of securities. Under SEC rules, a person is deemed to be a “beneficial owner” of a security if that person has or shares voting power or investment power, which includes the power to dispose of or to direct the disposition of such security. A person is also deemed to be a beneficial owner of any securities of which that person has a right to acquire beneficial ownership within 60 days. Securities that can be so acquired are deemed to be outstanding for purposes of computing such person’s ownership percentage, but not for purposes of computing any other person’s percentage. Under these rules, more than one person may be deemed to be a beneficial owner of the same securities, and a person may be deemed to be a beneficial owner of securities as to which such person has no economic interest.

Beneficial ownership of Common Stock is based on 23,050,450 shares of Common Stock issued and outstanding as of April 23, 2026.

Except as otherwise indicated in the footnotes, each of the beneficial owners listed has, to the Company’s knowledge, sole voting and investment power with respect to the indicated shares of Common Stock. Addresses for the beneficial owners are set forth in the footnotes to the table.

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Equity Compensation Plan Information

The following table summarizes information regarding the securities that may be issued under the 2012 Plan as of December 31, 2025:

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Item 13. Certain Relationships and Related Transactions, and Director Independence.

RELATED PERSON POLICY AND TRANSACTIONS

Related Person Transactions Policy and Procedures

In the ordinary course of the Company’s business, the Company may from time to time enter into transactions with its directors, officers and 5% or greater stockholders. The Audit Committee is responsible for approving related party transactions, as defined in applicable rules promulgated by the SEC. Our Audit Committee operates under a written charter pursuant to which all related party transactions are reviewed for potential conflicts of interest situations. Such transactions must be approved by our Audit Committee prior to consummation.

Related Person Transactions

Other than as described below, during the years ended December 31, 2025, and 2024, the Company did not enter into any related person transactions.

Weichai

Weichai America Corp. (“Weichai America”), a wholly-owned subsidiary of Weichai Power Co., Ltd. (HK2338, SZ000338) (herein collectively referred to as “Weichai”), owns approximately 46.0% of the outstanding shares of the Company’s Common Stock as of December 31, 2025. For a detailed description of the Company’s historical transactions with Weichai, including the Share Purchase Agreement, the Investor Rights Agreement (the “Rights Agreement”), the Shareholders Agreement with the Founders, and the Shareholder Loan Agreement, see Note 1 (Stock Ownership and Control), Note 3 (Weichai Transactions) and Note 16 (Related Party Transactions) to the Consolidated Financial Statements included in the Original 10-K.

The Rights Agreement provides Weichai with representation on the Company’s Board and management representation rights. As of the date of this filing, Weichai has four representatives on the Board, which constitutes the majority of the directors serving on the Board.

The Company and Weichai executed a strategic Collaboration Agreement on March 20, 2017, as amended (the “Collaboration Agreement”), in order to achieve their respective strategic objectives and enhance the strategic cooperation alliance to share experiences, expertise and resources. The Collaboration Agreement expired on March 20, 2026. The Company has received a renewal notice from Weichai and is in the process of negotiating the renewal of the Collaboration Agreement; however, no formal extension has been executed as of the date of this filing. The Company’s sales to Weichai were $1.3 million and $1.8 million during 2025 and 2024, respectively. The Company purchased $39.8 million and $21.5 million of inventory from Weichai during 2025 and 2024, respectively.

In connection with the Revolving Credit Agreement, on August 30, 2024, the Company also entered into a new SLA with Weichai, which allowed the Company to borrow up to $105.0 million and expired August 31, 2025. Borrowings under the SLA incurred interest at the applicable SOFR, plus 4.05% per annum. If the interest rate for any loan was lower than Weichai’s borrowing cost, the interest rate for such loan would be equal to Weichai’s borrowing cost plus 1.0%. The borrowing requests made under the SLA were subject to Weichai’s discretionary approval. The payment of the borrowings under the SLA was subordinated in all respects to the Revolving Credit Agreement with the exception that the Company was allowed to make a single payment of $10.0 million to Weichai. The $60.0 million portion of the initial advance under the Revolving Credit Agreement was applied to pay all principal, interest, and other amounts outstanding under the Shareholder’s Loan Agreements that the Company was previously party to with Weichai except for $25.0 million. In January 2025, the Company amended the Revolving Credit Agreement. After the amendment date, the Company was able to repay the outstanding balance under the SLA in principal and interest provided there are no new borrowings under the SLA. In June 2025, the Company made the final payment of outstanding balances and fully repaid the SLA.

In January 2022, PSI and Société Internationale des Moteurs Baudouin (“Baudouin”), a France-based marine engine manufacturing subsidiary of Weichai Power, entered into an international distribution and sales agreement which enables Baudouin to bring PSI’s power systems line of products into the European, Middle Eastern, and African markets, which resulted in $1.2 million of sales during the year ended December 31, 2025. Beginning January 2024, this agreement automatically extends for additional one-year terms unless notice is given by one of the parties. In addition to sales, Baudouin will manage service, support, warranty claims, and technical requests.

In January 2025, the Company entered into a five-year purchase agreement with SWIEC, for the exclusive purchase and distribution of certain engine and engine components for the fulfillment of a contract with a customer in North America. The supply agreement includes annual minimum requirements of products ordered during the initial term. If all minimum targets are met within the first three-year periods, the contract may be negotiated to extend beyond the five-year initial term. The annual minimum requirements are as follows:

In February 2025, the Company entered into the MOR agreement with Weichai. The MOR agreement requires the Company to pay Weichai a fee of 1.75% of gross revenues generated by the sale of certain engines manufactured by Weichai. Fees are due on a quarterly basis. The 2025 fee is $0.1 million. The MOR agreement expires in December 2029.

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During the year ended December 31, 2025, PSI and KION North America Corporation (“KNA”), a subsidiary of Weichai, were negotiating the terms of an agreement for PSI to develop and supply a 2.4L dual-fuel engine for use by KNA in the production of materials handling equipment. Prior to entering into a written development agreement, KNA suspended its plans to purchase the engine. PSI had completed significant development milestones at the time of suspension. Effective December 31,2025, the parties entered into a settlement agreement under which KNA paid approximately $0.5 million to resolve PSI’s claims for development costs incurred. Under the settlement agreement, KNA retains the right to resume development through December 31, 2028, and is under no obligation to do so.

Director Independence

The Board has determined that the Company is a “controlled company,” as defined in Rule 5615(c)(1) of the Nasdaq Marketplace Rules. The Board has based this determination on the fact that Weichai, through its direct ownership of approximately 46% of the Company’s outstanding Common Stock, combined with enforceable irrevocable proxies and voting agreements over the Founders’ shares pursuant to the Shareholders Agreement dated March 20, 2017, holds more than 50% of the voting power for the election of directors. The Company and Weichai have entered into a Shareholders Agreement with the Company’s founders (the “Founders”), pursuant to which the Founders have agreed to vote in favor of Weichai’s designees to the Board and for certain other matters. The Founders currently beneficially own at least approximately 6.3% of the Company’s Common Stock as of September 18, 2025. Under the Nasdaq rules, a company where more than 50% of the voting power for the election of directors is held by an individual, group or another company is a “controlled company” and may elect not to comply with certain Nasdaq corporate governance requirements, including:

In addition to the Nasdaq independence requirements, the Company also applies the independence guidelines set forth in its Corporate Governance Guidelines, which are available on the Company’s website at www.psiengines.com in the “Investors” section, under “Governance” and which are substantially similar to the Nasdaq’s director independence requirements and “controlled company” exemptions. Consistent with this requirement, based on the review and recommendation of the Nominating Committee, the Board reviewed all relevant identified transactions or relationships between each of the Company’s directors, former directors, or any of their family members, and PSI, the Company’s senior management and the Company’s independent registered public accounting firm, and has affirmatively determined that each of Messrs. He, Simpkins and Ms. Shea meet the standards of independence under the applicable Nasdaq listing standards. In making this determination, the Board found Messrs. He, Simpkins and Ms. Shea to be free of any relationship that would impair their individual exercise of independent judgment with regard to the Company. The Board has also determined that each member of its Audit Committee is independent under Nasdaq Rule 5605(a)(2). The Board found that Messrs. Jiwen Zhang, Zhao Jin, Xuesen Yang and Fuzhang Yu are not independent under the applicable Nasdaq listing standards.

Item 14. Principal Accounting Fees and Services.

AUDIT-RELATED MATTERS

Independent Registered Public Accounting Firm Fees

The following table shows the fees for professional services rendered to us by BDO USA, P.C. (“BDO”) for services in respect of the years ended December 31, 2025, and 2024.

In accordance with its charter, the Audit Committee approved in advance all audit services provided by the Company’s independent registered public accounting firm for fiscal year 2025.

Pre-Approval Policy and Procedures

In accordance with its charter, the Audit Committee approves in advance all audit and non-audit services to be provided by the Company’s independent registered public accounting firm.

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PART IV

EXHIBIT INDEX

The following documents listed below that have been previously filed with the SEC (1934 Act File No. 001-35944) are incorporated herein by reference:

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None.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this Report to be signed on its behalf by the undersigned, thereunto duly authorized, on the 30^th day of April 2026.

Pursuant to the requirements of the Securities Exchange Act of 1934, this Report has been signed below by the following persons on behalf of the Registrant and in the capacities indicated on the 30^th day of April 2026.

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