2000,50 4stroke,runs poor

[spike1953]

my 50hp yamaha 4stroke just wont run at idle and drives me nuts.had dealer rebuild carbs,put in new needles,ran good at idle but not top end.went back next season,he rebuilt again,another 300 plus dollars n it still runs bad.all I hear is bad gas causes the prob n carbs r gonna need replaced.i have external filter n gas with no ethanol.any answers or suggestions.i hate to trade it off it don't have a lot of hours on it and I don't know what I would buy.great motor for lots of years.stressing me out.Thanks,Spike

[boscoe99]

Did it run poorly right after the mechanic worked on it or did it start running poorly over time, however short the time might have been?

And describe what it does/how it runs poorly at WOT please.

And if I understood it correctly, the motor run good for years but now is not running so well?

Do you know if the mechanic ultrasonically cleaned the carburetors or did he just blow some magic juice through them?

[spike1953]

left dealer,drove 100 miles n put it in water n one of the carbs was leakin like crazy,called him he told me to let it run n pull the gas line off n it would quit leakin which it did,but still didin run rite.I m not aware of how he cleaned the carbs but doubt ultrasonic as I had never heard of that.the dealer is well respected in our area but I am not happy at this time

[spike1953]

it runs poorly when I am tryin to idle through brushy areas wen I m fhishin n at higher end speed it acts like it is luggin n not runnin free n easy like it used to if that makes any sense.thanks