Exhibit 10.8

April 29, 2011

The Investors party to the

Purchase Agreement referred to below

Ladies and Gentlemen:

This Agreement (this “Agreement”) is being delivered to you in connection with
the proposed purchase agreement (as such agreement may hereafter be amended from
time to time, the “Purchase Agreement”) to be entered into by Power Solutions
International, Inc., a Nevada corporation (the “Company”), and the investors
named therein (the “Investors”), which, among other things, provides for the
issuance and sale by the Company of certain of its securities to the Investors.
Capitalized terms used herein have the respective meanings ascribed thereto in
the Purchase Agreement unless otherwise defined herein.

As a condition to the Investors’ willingness to enter into the Purchase
Agreement, the Investors have required that the undersigned enter into this
Agreement. In order to induce the Investors to enter into the Purchase
Agreement, the undersigned hereby agrees that, it will not, other than in
connection with the Merger and the Stock Repurchase, during the period
commencing on the date of the Purchase Agreement and ending on the earlier of
(i) the termination thereof and (ii) 180 days after the Effective Date (the
“Lock-Up Period”), (1) offer, hypothecate, pledge, sell, contract or agree to
sell, sell any option or contract to purchase, purchase any option or contract
to sell, grant any option, right or warrant to purchase, lend, or otherwise
transfer or dispose of or agree to transfer or dispose of, directly or
indirectly, or file (or participate in the filing of) a registration statement
with the Securities and Exchange Commission (the “Commission”) in respect of, or
establish or increase a put equivalent position or liquidate or decrease a call
equivalent position within the meaning of Section 16 of the Securities Exchange
Act of 1934, as amended, and the rules and regulations of the Commission
promulgated thereunder (the “Exchange Act”) with respect to, any shares of
Common Stock or any securities of the Company that are substantially similar to
Common Stock, or any securities convertible into or exercisable or exchangeable
for, or any warrants or other rights to purchase, the foregoing (including,
without limitation, the Series A Preferred Stock), or (2) enter into any swap or
other arrangement that transfers to another, in whole or in part, any of the
economic consequences of ownership of the Common Stock or Series A Preferred
Stock or any other securities of the Company that are substantially similar to
Common Stock, or any securities convertible into or exchangeable or exercisable
for, or any warrants or other rights to purchase, the foregoing, whether any
such transaction described in clause (1) or (2) above is to be settled by
delivery of Common Stock, Series A Preferred Stock or other securities, in cash
or otherwise or (3) publicly announce an intention to effect any transaction
specified in clause (1) or (2). The foregoing sentence shall not apply to
(a) the Purchase and Sale Agreement, dated as of April 29, 2011, by and between
Gary Winemaster and Thomas Somodi, and the transfers of Common Stock as
contemplated thereby or (b) transfers of shares of Common Stock or any security
convertible into Common Stock (including, without limitation, the Series A
Preferred Stock) as a

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bona fide gift, by will or intestacy or to a member of the “immediate family”
(as defined below) of the undersigned or to a family partnership or trust for
the benefit of the undersigned and/or one or more members of the immediate
family of the undersigned or to any other person who is, or is to become, an
officer, director or other affiliate of the Company; provided that in the case
of any transfer or distribution pursuant to clause (b) each donee, distributee
or other transferee shall agree in writing to be bound by the terms of this
agreement with respect to any securities so transferred. The undersigned hereby
waives any rights the undersigned may have to require registration of Common
Stock during the Lock-Up Period. In addition, the undersigned agrees that it
will not, during the Lock-Up Period, make any demand for or exercise any right
with respect to, the registration of any shares of Common Stock or any security
convertible into or exercisable or exchangeable for Common Stock (including,
without limitation, the Series A Preferred Stock). The undersigned also agrees
and consents to the entry of stop transfer instructions with the Company’s
transfer agent and registrar against the transfer of the undersigned’s shares of
Common Stock or Series A Preferred Stock except in compliance with the foregoing
restrictions. As used herein, “immediate family” shall mean the spouse, any
lineal descendent, father, mother, brother or sister of the undersigned.

No provision in this agreement shall be deemed to restrict or prohibit the
exercise or exchange by the undersigned of any option or warrant to acquire
shares of Common Stock, or any other security exchangeable or exercisable for,
or convertible into, Common Stock, provided that any Common Stock acquired on
such exercise or exchange will be subject to the restrictions provided for in
this agreement. In addition, no provision herein shall be deemed to restrict or
prohibit the entry into or modification of a so-called “10b5-1 plan” at any time
(other than the entry into or modification of such a plan in such a manner as to
cause the sale of any shares of Common Stock or any securities convertible into
or exercisable or exchangeable for Common Stock within the Lock-Up Period);
provided that no sales or transfers may be made under such plan until the
Lock-Up Period ends or this agreement is terminated in accordance with its
terms.

The undersigned acknowledges that the Investors are relying upon this agreement
in entering into the Purchase Agreement and consummating the transactions
contemplated thereby. No amendment, modification or waiver of the terms of this
Agreement shall be effective unless consented to by the Required Investors in
writing.

The undersigned acknowledges that if the undersigned fails to perform any of its
obligations under this Agreement, immediate and irreparable harm or injury would
be caused to the Investors for which money damages would not be an adequate
remedy. In such event, the undersigned agrees that each Investor shall have the
right, in addition to any other rights it may have, to specific performance of
this Agreement. Accordingly, should any Investor institute an action or
proceeding seeking specific enforcement of the provisions hereof, the
undersigned hereby waives the claim or defense that such Investor has an
adequate remedy at law and hereby agrees not to assert in any such action or
proceeding the claim or defense that such a remedy at law exists.

This agreement shall be governed by and construed in accordance with the laws of
the State of New York, without regard to the conflict of laws principles
thereof.

[signature page follows]

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The undersigned further understands that this agreement is irrevocable and shall
be binding upon the undersigned’s heirs, legal representatives, successors and
assigns.

 

Very truly yours,

 

(Name)

 

(Address)