Originally Posted By: SecondMonkey
Due to the insane prices of Mercury brand oil I will be using Pennzoil 2 cycle oil in my antique Mercury outboard this year mixed at 32:1. Pennzoil semi synthetic is $15/gallon, Pennzoil regular is $12/gallon. May not seem like much of a difference, but I will be burning a LOT of it, and the premium gas already hurts bad enough.
So my question is, what extra good is a semi synthetic in an outboard motor? Usually I consider synthetics better for cold starts and longer OCIs, but obviously that doesn't apply to a 2 stroke. Will the semi keep the engine cleaner? Less smoke? Or will I proably not notice a difference at all?
Many years ago Trailer Boat Magazine did an article discussing among other things, using current oil in older engines. To the best of my memory this was the jest of the deal. Back in the 40's, and 50's the ratios were in the area of 16-1, 24-1, and 32-1. These ratios were with current technology 30w motor oil. They didn't even have a dedicated two cycle marine oil. At the time of the article I think that TCW-2 was the standard. Now I think we are still at tcw-3. I'm not up to date as I don't run outboards anymore. Anyhew, any of the older engines regardless of manufacturers recommended ratios can be run at a ratio of 50-1 due to todays oils being superior to what was available at the time of the engines manufacture. Trailer Boat magazine may be able to help you with a re-print. Perhaps you can find it free on the web with some searching. Phillips Injex is a low smoke high performance oil that is low smoke, and I think re-packages for OMC/Bombardier. I bought my Phillips at
http://www.harveyoil.com Pennzoil Premium Plus may the the source for Mercury Premium Plus, and performs great as well. Remember that the marine engine manufacturers are just that, and they are not in the oil business. If you don't feel safe with the 50-1 run where you feel comfortable. A modern outboard with the carbs set up right, and a 50-1 ratio will usually only smoke when cold. A modern outboard will usually need the choke when the engine is cold. If it does not, you are probably too rich, stinky, will smoke, and probably add carbon to the combustion chamber. It has been my experience that the leaner you can set the mixture screws, the more crisp the throttle response will be. I hope this is of some help. I don 't think that you need a semi, but whatever makes you comfortable.
