16mm
carb could be just little to small for that 5hp big block. I would go with a 22mm
carb like this. you can find them on
ebay and they use mikuni jets and pilots and easy to tune. also has a choke setup that works pretty slick once your engine is dial in correct. should take only one pull and starts all the time.
I still run a cheap 19mm on my briggs
bike I built and it's a real pooch,need to up grade someday...lol also that
carb only has a choke lever and no high idle when cold running it. 22mm mikuni/clone carb runs like a
car choke with high idle until you want to take it off. I have notes some of the small cheaper
carb's don't have this feature.(like my briggs
bike)