gas/oli mix

[loganmallory]

hi. i have a 1972 johnson 25hp and a 1960ish johnson 5.5hp. does anyone know what mixture i can use in a single tank to fuel both motors? i would like to use the 5.5 as a kicker and dont want to bring 2 tanks. thanks for any input you could provide.

 

[Franki]

Re: gas/oli mix

Well, OMC have stated that any of their motors can run at 50:1, but if you want some piece of mind, you could safely run 32:1...<br /><br />Alot of early OMC were stated 24:1, but oil is alot better nowdays.. and as I said, OMC have stated that any of their motors could run 50:1.. (read that on this very list.)<br /><br />Or, even better, mix 50:1, and if your main motor dies, double the oil <br /><br />rgds<br /><br />frank

 

[JB]

Re: gas/oli mix

Hi, Logan.<br /><br />Frank is very close, but in your case it makes a difference.<br /><br />Engines manufactured before 1964 have sleeve bearings rather than needles. Though the book calls for 24:1 in those engines, new oil permits 32:1. I am unaware that any official statement was ever made by OMC allowing for 50:1 in those older engines. I could be wrong.<br /><br />Any OMC engine made AFTER 1964 can use 50:1. I think that is the statement Frank read and took it to mean any OMC.<br /><br />Good luck.

 

[Tracy Coleman]

Re: gas/oli mix

JB There a lot of engines OMC pre-1964 that have needle bearings, say, 10hp, 15hp, 18hp, 25hp, 30hp, 40hp, 50hp, 75hp. Before the TwoCycle-Watercooled (TCW) standard. Automotive 30wt, non-detergent oil was the diet at 24/1. A noticeble<br />exception was Kendall outboard oil that a friend of mine ran his 1960 Merc 800 on 50/1 from day one for 6 or 8 years that I saw it run. No smoke, no problems. Of course, engines with bronze bushings, benefit from the excess oil helping to<br />seal the crankshaft mains. One of the best trolling engines, 1956-58 7 1/2 did real well on 24/1. But when they got a lot of hours on them, the aluminum rods gave out. <br />Backfire