It is a mariner 40hp.

Model 40l  6e9 l 361765.



Also wondering what yamaha parts cross over.

I'll find out for you Thursday when I get back to work if I can't find anything on the internetz today.
With a serial number of 6 digit numerals only, I'm going to guess, without looking it up, it's from the mid to late 70's.
ETA - Upon a bit of research, it looks like it was made in the 80's or 90's using a Yamaha powerhead and Mercury lower unit. I'm making this assessment from pics on this page.
The powerhead itself looks to be pure Yamaha but the lower cowling has a Mercury fuel fitting and safety kill lanyard switch. The mid section and lower unit looks to be Mercury. A Mercury dealer can get any parts you may need for it as long as it's not "NLA" no longer available. In that case reference Yamaha parts for the powerhead and Merc parts for the lower unit.

Thank you.



Yeah these motor are crazy. Some even have yammie lower units.

But they run forever.



 

Ok, I can't nail down a mfg date, but it is pure Yamaha. The gear case and water pump are pure Yamaha. So in effect, it's a Yamaha in Mariner paint.
I'm going to guess it was made in the late 80's to mid 90's. Hope this helps.
KB

Thanks.