Here are some things I learned about Yamaha's RX-1 four (4) cylinder sled engines and the carbs that feed it.
There are some changes that where made from early 03' float bowls. All 04' -05' models had
the carb float bowl update as standard issue after the 03' update. This float bowl update was done to resolve hard
landing throttle stumbles and also to prevent fuel starvation issues on steep hill climbs. Something to consider
for those engines converted to aviation. Here are some pictures of the carb rack I updated the float bowls on myself
having two (2) sets of carbs.....late 03' and 05' warrior carbs. The carb bodies are exactly the same in all other regards
except the float bowls, needle jet and main jet. I am also including screen shots of info found else where on the net
on this subject matter. Hope this helps some who need or want info on these sweet conversions of an engine.