+1 rupedoggy- Rebuild the carb...
I recently did the upgrade to both my W/T 61's too, well worth it IMO!
Had some trouble running with one orig carb too, bought a cheap chinese AM too, to try (also as a spare)
it works, but it is very touchy. 1/8th turn either way and 'bam' it just dies-
found out its missing the diaphram gasket- (how do you say "doh" in chinese) lol.
But it does work for now...
Keep at it you'll get it!