Re: 50:1 to lean?
It's generally thought that outboard oil is not a good choice for the reason given above. It is formulated for water cooled engines that do not reach the operating temperatures encounted with an air cooled one. Therefore you might see some degradation of lubrication quality due to excessive heat.
That said, you'd be advised to read the lable on the container, or research the oil of choice because some marine oils are in fact suitable for both water and air cooled engines but confirm that before trusting it in your bike engine. Also always follow the oil makers recommendations regarding mix ratio.
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