Re: Johnson 1958 18 hp Home › Forum › Ask A Member › Johnson 1958 18 hp › Re: Johnson 1958 18 hp shane-r13Replies: 125Topics: 21 September 21, 2018 at 3:36 pm #83316 My 1959 Evinrude 18hp Golden Jubilee LOW (stored since 1975) hour motor has 125 psi top and 122 psi bottom. So I would say a NOS should be higher.