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Semi synthetic vs full synthetic 2 stroke oil

Hello everyone,
I have a 1992 Yamaha 40hp 2 stroke that I got for a project a year ago. Finally brought back to life I took it to the lake yesterday and it ran it’s best so far. I put a full tank of fuel through it using Lucas semi synthetic 2 stroke oil. The more it ran the better it got. Very little smoke at startup and that’s all. The exhaust goes out of the new prop which is clean. Not even a streak of black on it. Needless to say I like the oil but thinking of trying their full synthetic which states that it exceeds all outboard manufacturers standards but doesn’t have the TCW3 on it like the semi synthetic. Does anyone have any experience with synthetic 2 stroke for outboards that could advise me on the subject? I’m trying to get the cleanest burning , lowest carbon and the best firing oil I can that’ll do a good job protecting my engine. Also I’ll have to purchase a gallon of the full synthetic instead of a pint just to try it.Thanks for any advice.
 
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Also want to go to synthetic in the lower unit. The manual calls for hypoid sae90. All of the synthetic lu oil seems to be 75w90 or 80w90. Would it be safe to use one of these?
 
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