Yes. The financing will have to come by way of a non-recourse loan. A non-recourse loan is a method of financing in which the 401(k) participant will not be needed to personally guarantee the loan, nor will the other assets of the borrower (the Solo 401k) be used to secure the loan. The only action a lender can take in case of default of the loan is to acquire the asset on which the money was loaned.