If you really suspect it's the stock carb, clean out all the gas, wrap it up real nice, put it in a box and ship it to BFE! Once those carbs decide to take a dump it's virtually pointless to try and fix em, they just become good rc boat anchors.
Now this is horribly untrue...it is usually the diaphrams that get cracked or dried out...with some patience the carb can be cleaned and rebuilt in a couple hours, you can even do it on some plastic in your living room while watching the game...then they are perfect for another 75K - 100K miles...
I've found that the gallon style can of parts cleaner is the perfect size for dipping the dissassembled carb into...comes out like new!