1962 evinrude 18hp fuel/oil mix

Hey everybody. I've been getting info off this forum for some time now but need a little help for few particular questions. I have a 1966 evinrude 18 horse that that the pistons went bad on for some reason, I always used a 50:1 mix for this motor but somewhere down the line I think the powerhead overheated but I don't know why or how because I always tried to keep a good eye on my impeller and fuel mix. Anyway, I come across a 1962 evinrude 18hp the other day and purchased it off craigslist for $60, taking a chance on it because the owner couldn't get it running. I brought it home and cleaned the carb out because the needle valve was stuck which was the only major problem so far. With plenty of unimportant rambling, I have two questions: 1) does the 1962 evinrude 18hp use a 50:1 mix or a richer mix?(I'm pretty sure it has needle bearings just like my 1966 model...) and 2) Are most all of the parts for the '66 and '62 interchangeable?...more specifically I would like to take the lower unit off my 66 and put it on the 62 because I just put a seal kit in it.

thanks in advance for the info

Both are short shafts. I have the 66 taken all the way apart. The cylinder walls appear to still be good but they did not pass the clearance specs between the rings and walls which is why I didn't spend the money to get more rings and bore out the walls.

50:1 did not come out till 1964. As for the actual internal differences, we could argue all day about that. Safe to say, use what it is supposed to have and you will be ok.

EDIT: "Supposed to have" has changed over the years. Today's TCW-3 outboard oil is far superior to the old SAE-30 they ran back in "The Day". Use it.

Mechanically there is not much difference between a 62 and a 66 motor.--------Going to 50:1 was a board room / sales department decision.-----------And NOTHING to do with the way these 2 motors were built !!!!

@kimcrwbr1; I was thinking about getting the .040 oversize pistons and rings but wouldn't i have to bore out the cylinder walls? The cheapest place i found to bore them out was about $150 total for both. I didnt think the motor was worth putting that much money into it, unless i'm looking or going about it wrong. By no means am I a professional at this. Some insight on why i took the '66 apart: The motor started and ran perfect on the first pull everytime, until it got warmed up. When i would go down the river at high idle after about 5 minutes, i guess the block would heat up then i would lose most of my power. It would still stay at high idle, but i would slow down tremendously. Anyways, i took it apart and came to the conclusion that the pistons were too far gone.

Anyone know the mix on the 1962 model 18hp, I do not have the manual on what it is "supposed to be"? 25:1, 40:1, 50:1? I will be using the quicksilver 2 cycle marine oil, stuff you can get at wal-mart. Any guidance on the mix is appreciated because I dont want to have another shot motor.

i ran a 67 evinrude 18 that was bought new and it ran 25-1....

?????-------------In 64 they went to 50:1 and it was a sales department decision.------Too many folks walked out of showrooms because the competion ran at 50:1.------And the general public believes that a 50:1 motor ---" must be built better "----Than a 24:1 motor !!!!!!-----Note , the same thing happened in the mid 1980's when suddenly they went to 100:1 without any change to motor parts !!!---We know what happened to those motors.------As I have said before internal workings of the motor and how the oil behaves is not well understood !

That is true. BUT, 50:1 was recommended ONLY if Evinrude or Johnson 50:1 oil was used (in that day). I heard it straight from an Evinrude engineer's mouth that "we just found out that they don't need as much oil as we thought they did". Of course, now the question becomes Is today's TCW-3 oil the same stuff as the original TCW oil, which later became TCW-2, now evolved again. Obviously, it is not. Then it becomes is it actually better? So many questions and so few actual answers. But lots of "experts". I usually stay out of these discussions, but now that I'm here, I will say that if I say use 50:1 in an older motor and someone does and the motor destructs, I'll be blamed for it. Even though the oil wasn't the real real reason for it tearing up. That's why I say use what the mfr said to use and you will be OK. What the mfr said was 24:1 up through 1963, 50:1 phased in, in 1964-up.

Going from 24:1 to EXACTLY half the oil would have to be a marketing decision and nothing to to with engineers.

I still own a 59 sea horse 18...ran it for 2 years on 50 to 1 TCW 3...no excessive wear and a lot less smoke....great motor.

See, here is why I avoid these oil discussions. Why are we arguing about all this anyway? Of course the marketing manager was the one who proposed the 50:1 ratio to meet the competition...which was Scott-McCulloch with their 100:1 oil. Merc had not yet gone to leaner mix. But don't think for a minute that Marketing acted on their own. They can propose the change, but Engineering had to sign off on it. The design and specifications buck stops with The Chief Engineer. Well, I suppose he reports to some higher authority also. In the manufacturing plant where I retired from, any changes in design or specifications had to be signed off on by Engineering, Marketing, Purchasing (me), and the Shop Manager. My head would have been in a basket if I had purchased some part or material that was not specified by Engineering specifications and passed QC (which also reported to Engineering).