BF 135 What engine oil do you use

Synthetic - Conventional
Brands

10W-30 Honda Engine oil.

This question comes up a lot and there is open debate on synthetics verses petroleum-based marine engine oils. If you closely follow the engine's maintenance schedule, it likely calls for changing the oil every 100 hours or every six months, whichever comes first. If you do that (which you definitely should) then in my opinion synthetic oil is a waste of money and is not any better for your engine. You can download the owners manual free from Honda Marine. http://marine.honda.com/support

That manual will like state that any 10W-30 motor oil the meets or exceeds API service classification SG or SH is fine. In the US, the API service classification must be posted on the oil container.