I have a Honda GVC160 mower running Redline 5w-40.
I was thinking about Motul 300V 15W50 - but then on the other hand why?
1.) It's a Honda
2.) It's not overly stressed running at 2800 or 2900 rpm mowing for 1-2 hours at the time
3.) HDEO 15W40 with enough zinc even in that aircooled engine is more than enough protection, to step it up maybe I'll use Delvac 1 5w40.
I find no difference in starting the Honda GCV at all with different oil weights, Honda's easystart one (max 2) slight pulls and it runs.