Re: Gas/Oil ratio for 1954 Johnson 3hp?
Hi Walt,<br /> Yes, my 50:1 remark was directed at the older Mercs. Most any Merc can handle it for awhile, as even back into the late 1940s they were "full-jeweled" - remember that one? I run my vintage (pre 1960) Mercs pretty hard so I like to up it to 32:1 for them, 20:1 for my racing stuff.<br /> As for the little Johnson JW, run it at 24:1 and it'll run forever. Keep in mind that those old babbit bearing motors (ALL OMC motors prior to 1955, and some into the early 1970s) need the extra oil not just for lubing, but also for sealing purposes. The tolerances on the old motors were a lot looser than the new ones and the oil helped cushion things, too. Simple rule - if it has babbit bearings on the rod journals, run it 24:1. If it has needle bearings, you can lan it out from there depending on where else needles and rollers can be found. For instance, a 1959 10hp OMC has needles in the upper main bearing and on the crank/rod journals, but still has bronze at the lower and center mains - better off at 32:1. The 5.5hp from the same year is all bronze bushings and bearings - run it 24:1. The 3hp motors didn't get any needle bearings until mid 1960s, and still used bronze bearings on the rods, center main, and lower main into the mid 1970s as it was updated to the 4hp - run them at 32:1.<br /><br />How about that for a long answer to a simple question??? I'll shut up now...<br />- Scott
