I've run two YF on my 39 GMC for years on a Nicson
The real problem is small parts
I've basically run the same carbs on both the trucks engines 228
and 302
But where do I get the small bits?
I'd really like to fine tune these instead of relying on their flexibility

I've both off now after the 39 started popin and fartin and I traced it to clogged carbs....

Nate has em cookin in some trick Yamaha stuff