When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. On the other hand, it's probably older than I am - and looks to be in better shape. Sapphire has a 1967 short shaft 6 Hp. . Ab has me burning nothing but the highest octane I can find: 91 and sometimes 94.
All I'm looking for is to get the right mix so this motor runs well and I don't break something. Very old motors may use a lower ratio. Older engines used 20:1 mix ratios. Does anybody has an expert advise on that question to back-up my deductions? Now my 1954 British Seagull 40 Plus is one stinky, noisy outboard. I know oils have improved. It was not the traditional Johnson Green nor the transitional Johnson Red but the new wizzbang traditional Johnson White.
See: Evinrude 1930 to 1979 This may be useful in associating a particular model number to a particular year. Refer to question 5 for information on oil. The service manual for the motor states using a fuel to oil ratio of 24:1!! Salt water environments, high-performance applications, and commercial usage require more frequent service and inspections. You can download a model-year guide at: 3 What is my sparkplug gap? I have to go changing my gear oil for peace of mind, even if I was told it was done by the previous owner. Martin, I have a 1987 9. I assumed Evinrude ran into trouble with the original recommendation and had to change it.
The official factory changeover date from 24:1 to 50:1 fuel mix was for the 1964 model year motors. The oil must be suspended evenly in the mix, so the engine gets lubricated evenly. With full tackle and gear plus me 190lbs I'll get anywhere from 19-23 mph on gps. Years ago oil quality was poor so more was neccessary to keep the engine lubricated but technology of oil has improved greatly allowing leaner oil mixtures and still providing good and even better lubrication. So far it is running fine but I may go to a 75 to 1 mix. But better sometimes does not include good.
Head for your manual for types of gasoline and octane rating your engine requires. It would be a shame to burn it up because I was too chintzy to pay for oil. I've been oiling it at 50:1. Works great when you're just topping off your tank. They have a chart onthe side with all the fuel ratios and how much oil to add for different amounts of gas.
Recommendations appeared to run between 30:1 and 50:1. Most of the newer engines run on leaded or unleaded. When we hear from the originator that he is hopelessly disappointed with the results he got, then you can email him and tell him where he went wrong by posting here. I've got the same motor! Open with a churchKey Forum posts represent the experience, opinion, and view of individual users. So I should be using a bit less than a pint I used far less than that when I took it out! Our two stroke outboards are mostly low compression engines. Whether this resulted in a drop of powerhead failures or not is not for me to decide….
For information about vintage motors and obsolete parts contact: Antique Outboard Motor Club P. You got a good motor, so take care of her and she will take care of you! Naturally they cost a little more. Motors with visible damage, corrosion, or missing items have very little worth and are often purchased just for spare parts. Buying a service manual from E-bay, found out the year and make of the outboard, will continue to research over the web. Click on your type of outboard and scroll down to the appropriate engine listing. I ran 30:1 to be safe and the engine ran poorly. Engines that have bushings should always be run on the richer 24:1 mixture regardless of todays oils vs yesterdays oils.
General rule is 1960 - 1964 - under 18 horse - 24:1. There is no hard and fast rule about how much oil to mix. Mix the gasoline and oil thoroughly. But I also know my little Elgin has bronze bushings for bearings, so I think I'll stick with 16:1. And then I read that somewhere in the 1960's, the recommended fuel oil mix went to 50:1.
I changed to 50:1 and the engine runs much better. After break-in, use 100:1 oil mixture. For example, my Elgin's manual calls for ordinary motor oil, so using modern oils would probably let me get away with a lot leaner mix. If you have knocking on a low compression engine with regular fuel than there is something wrong with your ignition timing. This is no big deal, as long as I avoid engine premature damages and maintain it easy to start. Proper engine operation and longevity are governed by the propeller.