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                                                                     Exhibit 3.5

                           CERTIFICATE OF FORMATION OF
                         GENERAC PORTABLE PRODUCTS, LLC


         This Certificate of Formation of GENERAC PORTABLE PRODUCTS, LLC (the
"LLC"), dated as of the 1st day of June, 1998, is being duly executed and filed
by Andrew M. Metcalf as an authorized person, to form a limited liability
company under the Delaware Limited Liability Company Act (6 Del.C. Section
18-101, et seq.).

                                       I.

         The name of the limited liability company is Generac Products, LLC.

                                       II.

         The address of the registered office of the LCC in the State of
Delaware is 1013 Centre Road, New Castle County, Wilmington, Delaware 19805.

                                      III.

         The name and address of the registered agent for service of process on
the LLC in the State of Delaware is Corporation Service Company, 1013 Centre
Road, New Castle County, Wilmington, Delaware 19805.

         IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Formation as of the date first written above.


                                             /s/ Andrew M. Metcalf
                                             -------------------------------
                                             Andrew M. Metcalf
                                             Authorized Person