Re: 1957 35 hp seahorse lower unit.
Rolmops - I'm guessing your leak is at the but ends of the spagetti seal. I followed the OEM method - cut the spagetti 1/32" long and seal the but ends and oring with 1000 sealer.<br />Actually, I cut the ends a little longer, mabey almost 1/16", after pre-squishing the spagetti into the corners of it's groove on the cap. I also used Permatex #3 (Aviation form-a-gasket) rather than 1000 sealer and applied it to the o-ring in addition to the spagetti seal. I belive a few others here use that rather than 1000 sealer for lower units.<br />I cleaned the surfaces and seals with acetone before applying sealer to them. Everything was surgically clean. The mating surfaces were checked for flatness and re-surfaced with a surface plate. Oh, ok - a 3/8" thick peice of glass with 320 grit 'glued' to it with water. My gearcase held 5psi no problem after I sealed it.<br /><br />There's other methods, for example like the Seloc manual method where you use RTV at the ends of the spagetti. I was cautioned here not to use that method. <br /><br />I remember reading somewhere to test these split gearcases with no more than 5psi of pressure. I think they recomended 3psi. I'm pretty sure that was from a later OEM manual at the library...<br /><br />Good luck!
