Have a 2002 trx350fm. Been leaking from carb overflow occasionally and has been getting worse. Had to replace starter brushes and decided to look into. Wasn’t dirty or sticking so I got a new float needle. Tried again and fuel comes out within seconds of turning fuel on. Replaced float per recommendation from dealer as that is the only other serviceable item. Still does it. The valve on the bowl is closed and does not leak and the overflow tube doesn’t appear to be leaking. Tried putting carb in a larger bowl to see what is happening with float exposed and filled through fuel line inlet. Float came up but did not stop fuel from passing through line and was well above where it should stop.
Dealer says the seat could be the cause but is not serviceable. Looks ok and it seals with the slightest pressure if held manually by hand or screwdriver. Seems I am down to relaxing the carburetor itself.

Looking for the carb it came with is around $350 part #16100-HN5-673. Google search comes up with part #16100-HN5-m41 for 2000-2006 but only shows as the oe for 2004 and up and only $150 new. I know the engines are the same but is there a difference between the two other than $200?