The oiling list shown above is in my 1980 OMC Parts and Accessories manual to and I for one have to whole heartedly disagree with their 24:1 recommendations for the JW, CD, and AD motors. They did get it right for the five horse TN motors at 16:1 though but these motors had already been obsolete for thirty years at the time of publication.
The Johnson JW, CD, and AD motors are constructed similar to the TN motors with no ball or roller bearings in them of any kind, only sleeve style bearings. Why should the oiling requirements change for these motors when they are so similar to the TN’s? I can see using TCW Generation 1 oil at 50:1 on ’64 and later 5.5 horse CD motors as they got needle bearings on the rods big ends in ’61 but still used sleeve bearings on the cranks mains until their demise in ’79 as a six horse but recommending 50:1 mix in these motors ‘Only If Johnson Lubricant Is Used’ is bordering on insanity, if it isn’t already.
Now lets look at the big picture. OMC was in business for one reason only, and that was to make money. That’s what all big businesses are about, profit. They are not your friend and couldn’t care less if your old motor burned out while out on the lake as chances are you would be buying a new replacement motor from either them or one of the other major players of the day. The odds were you would buy another OMC motor, either a Johnson or Evinrude, since you enjoyed your old one so much before it went South. Selling new motors is what their business was all about and more sales meant more corporate profit.
I’m not the only one who feels deep down this was a corporate ploy to help increase sales. I could be wrong but can’t help feeling a bit suspicious about it. Since the extinct AD and JW and CD motors kept running so well year after year on 16:1 mix, sales, as in profits, weren’t what they could be if these motors weren’t replaced more often. One way to get around this would be to nonchalantly help the motors wear out quicker, by recommending a leaner gas/oil mix. After all, 50:1 was the new normal in ’64 and who wanted to use a heavier 16:1 mix when 24;1 or even 50:1 could or might do the job using the new TCW oil?
These older motors were designed and built with an expected lifetime in mind. They weren’t supposed to be so reliable and keep on running year after year as this cut into company profits. I’m sure this is why OMC published these oiling recommendations, to help speed up the process. After all, to be successful in business, sometimes one has to make shrewd decisions.
Some of my personal experiences can back this up. As an owner of many of the above mentioned motors, I have found that the majority of the 16:1 TN, AD, CD, and JW motors in my stable are in excellent mechanical condition internally and only require a new set of rings to be transformed into reliable runners again while many of the later 50:1 six horse and three horse motors I see are literally worn out. Scuffed and scored pistons and cylinder walls seems to be the most common problem with these 50:1 motors with worn rod bearings coming in second. Why? I’ll put my money down on not enough oil in the mix.
That’s my rant for the day and I’m off my soap box now as I have stumps to dig out before the ground dries out. My trusty old 16:1 Pioneer (OMC) 1074 chainsaw will be in use today, and probably tomorrow to. And if it throws a chain, I have another one to use which I bought brand new 40+ years ago!
Yeah, Mumbles got it right. OMC was ruled by the “marketing department” aka advertising/sales. The employees that came up with this oiling guide probably weren’t even familiar with the older plain bearing models, oh well. It is this same marketing department that ruled in the 80s, which drove the 100:1 recommendation. I’m not trying to defend the engineering department, sure they made mistakes, but the marketing department ran the show…Unfortunately.
