I got a copy of the original owners manual for this motor and it says to mix 1/3 pint oil per gallon of gas. That would be one quart per six gallon tank which I believe would be 25:1. It also says to use SAE 30 outboard motor oil or SAE 30 grade automotive oil. It says "use only the recommended oil to gasoline mixture ratio regardless of the claims made for some lubricants. The person I bought the motor from said he was using 50:1 mixture of 2-cycle oil, or one pint per 6 gallon tank. This was also recommended by a boat dealer I called. Perhaps there is a significant difference in oils available now as compared to 1959. I'm hoping to hear from others who own or are experienced with this motor. What works best?Thanks
fishforbrains,Your findings were fairly accurate.The newer TCW3 oils are far better than what was once used and many people mix these older engines at 50:1.The original mix of your engine was 24:1.Whether you use 50:1 or not is a decission you'll have to make.If the previous owner had run this engine at 50:1 for a spell with no ill effects,I think you have your answer.
You have brought up a topic that is close to religion and politics for causing arguments.Your engine has roller bearings, so it's not an absolute 24:1 case as older engines would be.I run about a 32:1 mixture in mine. Maybe I would use 50:1 if buying a super-premium oil like Quicksilver. IMHO, just err on the (very) generous side of 50:1 and you may be OK.
I think you're gonna find that that engine has inserts, not roller bearings. I think roller bearings came along in '63 or '64. Still your call though. 25:1 or 50:1 or 37 1/2:1 .c/6Hooty
Wow! I had no idea this would be controversial. Who woulda' thunk?At any rate the original Lark powerhead bulletin lists the bearings as roller bearings but I don't know enough at this point to know the significance of that. Feel free to educate me. That's what I came for. Am I correct that more oil is better except if there is so much that the plugs get fouled. What are the other downsides of excessive oil other than environmental pollution. Is too little oil worse?I understand it can cause excessive engine wear and overheating which will ultimately ruin the engine. I'm curious if anyone can state that they used this mixture for this many years and had these problems or no prblems.
lubrication. the older the engine is, the more wear on the internal parts there is, requiring more lubricant to quote 'fill the gaps' on worn bearings and ring to cylinderspace.
fish-for -brains, The difference between roller or needle bearings as opposed to babbit or shell bearings is the open and oil accessible design of the needle or roller bearings verses the closed design of babbit bearings.The open design of the roller bearings allow them to more easily accept lubrication and require a less oil rich mix.They are also lower friction than babbit style bearings.
Fish-for-brains, your engine definitely has roller bearings throughout. Adding extra oil causes the engine to carbon up quicker. Of course that problem is easily solved by decarboning it more often.I've never been able to completely buy the 'babitt/roller' definition since the later model 60's 3 and 4hp's were babitt throughout, and rated for 50:1 from the factory. Mabey that's just a small hp engine thing though, since 5.5's went to rollers in '61, and the 10hp in '64 (the same year OMC went to 50:1?)There is a really good reason to use extra oil though - on a infrequently used engine, all that oil will afford you some internal corrosion resistance. I think that's the reason OMC dropped back from 100:1 to 50:1 in the late 80's.So, I guess I'm still sitting on the fence...
Fish...I also have a 1959 35 hp, and I have been following these types of discussions closely. My local dealer recommended 50:1 for the above reasons. I have been hesitant to run 50:1 all the time and usually split between 32 and 40. I will say that when I did run 50:1 (1 full tank) I saw no ill effects, and the engine ran nice and cool.As for the bearings, I have a 1960 Evinrude 40 hp parts motor (appears identical except for paint and bolt ons) and I took it apart to check the bearings. The mains and the big end of the con rods are definitely roller/needle, but I was not able to easily see the wrist pin bearings (most critical for lube?).I will probably keep running a fat 40:1 just in case. I have put at least 30 gallons of this mix (Quick silver) through the engine this summer w/ no probs.TE
Gas / Oil mixture 59 Evinrude 35 HP
The difference between roller or needle bearings as opposed to babbit or shell bearings is the open and oil accessible design of the needle or roller bearings verses the closed design of babbit bearings.
Linear Mode
