Small Engines (Lawn Mowers, etc.): tecumseh fuel/oil mixture, synthetic motor oil, two stroke engines

Question
Mr. Bridgers, I have a 1968 or 69 Otasco Flying-O 5.0hp outboard motor, with a Tecumseh motor.  The engine tag reads T-643-20A on the block.  The motor itself, is a Model 1908A, ser.#3C 305623.  I need to know the proper fuel/oil mixture ratio.  I also need a source for some literature on this motor/ outboard.  Any ideas.  Looks like a big chainsaw motor.
thanks,
Kris

Answer
Hello Kris:

All Two Stroke Engines will use a 50 to 1 Ratio using Today's Two Stroke Oils.  I once used an Old Chainsaw probably from the 1960s, that had a sticker on it that said to use a 25 to 1 Fuel/Oil Ratio, but that would have been using Two Stroke Oils of the Time Period the Chainsaw was Manufactured.  In that Chainsaw I used 50 to 1 Ratio with no problems.  Today's Two Stroke Oils compared to Yesteryears are more Efficient at Lubricating.  It is like comparing Today's Synthetic Motor Oil to Motor Oils of Decades ago.  All the Equipment I use in Landscaping, anything from a Weed Eater, Leaf Blower, Chainsaw, Hedge Trimmer, use 40 to 1 ratio, and I use all types of makes and models, Stihl, Homelite, Husqvarna, Shindaiwa, and Echo, Sears.  I mix up a 5 Gallon Fuel can and use it in all of the Equipment for my Customers and for my Landscaping. I like my Fuel/Oil Ratio a Little Heavy, so I use a 40:1 Ratio. Most of the 2 Cycle Outboard Engine of the 60's and 70's Use Either 25:1 or 32:1 Ratio. According to My Information for this Engine the Fuel Mix Ration was 32:1. You Should be Able to Use a 40:1 Ratio and have Little to No Problems. You can Contact Tecumseha and Speak to a Support Technician @ 800-558-5402 betwenn 8am EST and 5PM EST. He can Give you the Required Information for Ordering a Manual. If they are of No Assistance, then Let me Know and I will Locate the Information for you. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

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Respectfully

John