[SCHEDULE 13D/A] Power Solutions International, Inc. SEC Filing

Rhea-AI Filing Summary

Weichai-affiliated holders reported an open-market sale of Power Solutions International (PSIX) shares that reduced their combined stake to 48.7%. Weichai America, Weichai Power and Shandong Heavy Industry filed Amendment No. 7 to their Schedule 13D to disclose that Weichai America sold 251,983 shares under Rule 144 in two trading sessions on August 14-15, 2025. The filing lists the weighted average prices: $84.9758 on August 14 and $83.1604 on August 15, with transaction price ranges provided for each day. The aggregate post-sale beneficial ownership is reported as 11,211,841 shares, based on 23,029,846 shares outstanding as of July 31, 2025.

Insights

M&A Specialist

TL;DR: A meaningful stake reduction (>1%) was disclosed; still a near-majority position at 48.7%, which preserves strategic influence.

The disclosed sale of 251,983 shares by Weichai America, executed under Rule 144, reduced the reporting groups ownership to 48.7% of outstanding common stock. For M&A considerations, the group remains the single largest holder with substantial influence but below an outright majority, which may affect negotiation dynamics for any future control transactions or tender offers. The filing provides price detail by date, enabling assessment of market execution versus prevailing market prices.

Corporate Governance Expert

TL;DR: Transaction is a routine Rule 144 disposition but is material for governance because the groups stake crossed a >1% decrement threshold.

From a governance perspective, the Schedule 13D amendment appropriately discloses the open-market sales and maintains transparency about beneficial ownership. Although the groups voting power remains substantial at 48.7%, the reduction is material enough to warrant monitoring for potential changes in board influence or voting outcomes. The filing also commits to providing price-by-price execution details upon request, which supports regulatory compliance and shareholder transparency.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 7)

POWER SOLUTIONS INTERNATIONAL, INC.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

73933G202

(CUSIP Number)

Weichai America Corp.
Attn: Jinguang Liu (aka Jin Liu), 3100 Golf Road
Rolling Meadows, IL, 60008
(855-922-9001)

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

08/15/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 73933G202

1

Name of reporting person

Weichai America Corp.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

ILLINOIS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,211,841.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,211,841.00

11

Aggregate amount beneficially owned by each reporting person

11,211,841.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

48.7 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

1. The number of shares beneficially owned represents 11,211,841 shares of Common Stock held by the Reporting Persons. 2. The beneficial ownership percentage is calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended, based upon information from the Issuer's Quarterly Report on Form 10-Q filed on August 8, 2025 that, as of July 31, 2025, there were 23,029,846 shares of Common Stock outstanding.

SCHEDULE 13D

CUSIP No. 73933G202

1

Name of reporting person

Weichai Power Co., Ltd.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CHINA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,211,841.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,211,841.00

11

Aggregate amount beneficially owned by each reporting person

11,211,841.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

48.7 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

1. The number of shares beneficially owned represents 11,211,841 shares of Common Stock held by the Reporting Persons. 2. The beneficial ownership percentage is calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended, based upon information from the Issuer's Quarterly Report on Form 10-Q filed on August 8, 2025 that, as of July 31, 2025, there were 23,029,846 shares of Common Stock outstanding.

SCHEDULE 13D

CUSIP No. 73933G202

1

Name of reporting person

Shandong Heavy Industry Group Co., Ltd.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CHINA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,211,841.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,211,841.00

11

Aggregate amount beneficially owned by each reporting person

11,211,841.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

48.7 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

1. The number of shares beneficially owned represents 11,211,841 shares of Common Stock held by the Reporting Persons. 2. The beneficial ownership percentage is calculated in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended, based upon information from the Issuer's Quarterly Report on Form 10-Q filed on August 8, 2025 that, as of July 31, 2025, there were 23,029,846 shares of Common Stock outstanding.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.001 per share
(b)	Name of Issuer: POWER SOLUTIONS INTERNATIONAL, INC.
(c)	Address of Issuer's Principal Executive Offices: 201 Mittel Drive, Wood Dale, ILLINOIS , 60191.
Item 1 Comment: This constitutes Amendment No. 7 ("Amendment No. 7") to the Schedule 13D relating to the shares of Common Stock of Power Solutions International, Inc. (the "Issuer") as filed with the SEC on April 7, 2017, as amended by Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4, Amendment No. 5 and Amendment No. 6 as filed with the SEC on August 10, 2017, December 5, 2017, August 31, 2018, October 3, 2018, April 26, 2019 and August 15, 2025, respectively (as so amended, the "Schedule 13D"), by Weichai America Corp. ("Weichai America"), Weichai Power Co., Ltd. ("Weichai Power"), and Shandong Heavy Industry Group Co., Ltd. ("SHIG") (each of Weichai America, Weichai Power, and SHIG a "Reporting Person" and collectively the "Reporting Persons"). Capitalized terms used in this Amendment No. 7 without being defined herein have the respective meanings given to them in the Schedule 13D. This Amendment No. 7 is being filed by the Reporting Persons to report the open market sales by Weichai America of an aggregate of 251,983 shares of the Issuer's Common Stock pursuant to Rule 144 under the Securities Act of 1933, as amended ("Rule 144"), through a broker-dealer from August 14, 2025 to August 15, 2025 (the "Sales"). The Sales resulted in a decrease of over one percent (1%) in the aggregate percentage ownership reported by the Reporting Persons in Amendment No. 6 to the Schedule 13D. Except as specifically amended by this Amendment No. 7, this Schedule 13D is not modified or revised in any material way.
Item 4.	Purpose of Transaction
	Item 4 is hereby amended and supplemented by adding the following: On August 8, 2025, Weichai Amercia filed a notice with the SEC on Form 144 relating to the proposed sale of up to 1,150,000 shares of Common Stock in accordance with Rule 144. From August 14, 2025 to August 15, 2025, the Reporting Persons sold an aggregate of 251,983 shares of Common Stock in a series of open-market transactions through a broker-dealer.
Item 5.	Interest in Securities of the Issuer
(a)	Item 5(a) is hereby amended and restated as set forth below: The Reporting Persons may be deemed to beneficially own the shares of Common Stock of the Issuer as set forth on Exhibit Q hereto.
(b)	Item 5(b) is hereby amended and restated as set forth below: The Reporting Persons may be deemed to beneficially own the shares of Common Stock of the Issuer as set forth on Exhibit Q hereto.
(c)	Item 5(c) is hereby amended and restated as set forth below: In connection with the Sales, Weichai America sold 251,983 shares of Common Stock in a series of open-market transactions, through a broker-dealer, pursuant to Rule 144. Details by date, listing the number of shares of Common Stock disposed of and the weighted average price per share, are provided below. August 14, 2025 - Shares Disposed of: 135,846 - Weighted Average Price Per Share: $84.9758 (multiple transactions at prices ranging from $81.58 to $90.3675 inclusive) August 15, 2025 - Shares Disposed of: 116,137 - Weighted Average Price Per Share: $83.1604 (multiple transactions at prices ranging from $80.00 to $86.07 inclusive) The Reporting Persons undertake to provide, upon request by the staff of the SEC, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price for each of the above transactions. Except as set forth above, none of the Reporting Persons has effected any transaction in shares of Common Stock since the most recent filing of Schedule 13D.
(d)	Not Applicable.
(e)	Not Applicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit Q - Beneficial Ownership of the Reporting Persons in the Securities of Power Solutions International, Inc. Exhibit R - Powers of Attorney (Weichai Power Co., Ltd.), incorporated by reference to Exhibit 24.1 to the Form 4 filed by Reporting Persons with the Securities and Exchange Commission on August 14, 2025. Exhibit S - Power of Attorney (Shandong Heavy Industry Group Co., Ltd.), incorporated by reference to Exhibit 24.2 to the Form 4 filed by Reporting Persons with the Securities and Exchange Commission on August 14, 2025.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Weichai America Corp.

Signature:	/s/ Jinguang Liu (aka Jin Liu)
Name/Title:	Jinguang Liu (aka Jin Liu), Chief Financial Officer
Date:	08/19/2025

Weichai Power Co., Ltd.

Signature:	/s/ Chenglong Sun
Name/Title:	Chenglong Sun, Authorized Representative
Date:	08/19/2025

Shandong Heavy Industry Group Co., Ltd.

Signature:	/s/ Chenglong Sun
Name/Title:	Chenglong Sun, Authorized Representative
Date:	08/19/2025

FAQ

What did Weichai America disclose in the Schedule 13D/A for PSIX?

The filing discloses that Weichai America sold an aggregate of 251,983 shares of PSIX in open-market transactions on August 14-15, 2025 pursuant to Rule 144.

How much ownership do the reporting persons now hold in PSIX?

The reporting persons beneficially own 11,211,841 shares, representing 48.7% of the 23,029,846 shares outstanding as of July 31, 2025.

At what prices were the PSIX shares sold on August 14-15, 2025?

Weighted average price per share was $84.9758 on August 14 (range $81.58 to $90.3675) and $83.1604 on August 15 (range $80.00 to $86.07).

Was this sale conducted under Rule 144?

Yes. The filing states the shares were sold pursuant to Rule 144 under the Securities Act of 1933.

Will the reporting persons provide more granular execution details?

Yes. The reporting persons undertake to provide, upon request by the SEC staff, the issuer, or a security holder, full information regarding the number of shares sold at each separate price.