2000 yami50 4 str stalls and misses in mid-range

[mfc9459]

I have a 2000 50 yamaha 4 stroke that stalls when put in gear, runs rough in mid-range , meets specs at wide open throttle . I drained carbs in late fall as I do evey year
,fresh gas. water seperator/filter new as every year.

Any ideas, I need this fixed by tomorrow.

 

[cousinabe]

Re: 2000 yami50 4 str stalls and misses in mid-range

http://www.boats.net/parts/search/Yamaha/Outboard/2000/F50TLRY/CARBURETOR/parts.html

sounds like your slow air adjusting screw needs to be cleaned out. these tend to get gummed up over storage.
take a small drill bit, drill out the brass plug #33. before taking out the slow air adjusting screw, count how many turns in(righty tighty) it takes to get to a lightly seated position. RECORD THIS NUMBER. Next, unscrew it out and clean passage with carb cleaner. make sure screw tip is clean. screw in till lightly seated and then back out to the number of turns you recorded.

do this for all four carbs.