4 stroke Yamaha 50HP -Runs rough at all throttle levels

Year and model?

One cylinder may be starved for oil causing the noise your hearing.

Make sure carbs are clean,check exhaust tube isn't blocked,check resistance readings on charge coil,make sure filters are clean,no fuel leaks in fuel line,tank has open breather,fuel connector not blocked.if this doesn't solve the problem could be faulty cdi unit

sounds like a bad coil or trigger. Find the offending cylinder with a timing light and physically move the coil to a good firing cylinder. If the problem follows the coil, you have it, if not you need a trigger,

i have had this on mine and it was a sort of insect that made a mud nest in the small hole and it blocked the hole up ,try poking it out with a bit of wire

clean your carbs etc !! fit a water fuel seperator inline from tank to stop problems !

Did you change your fuel? If you are trying to use the same fuel from last year without being stabilized then that would cause your problem. I know that you already had your carbs cleaned but it sounds like something els got plugged up in them. If you have fresh fuel then I would take the carbs back apart and check your jets in the carb to ensure that there is nothing obstructing any of the orifaces in the jets. I am a boat mechanic and I have had to take carbs apart 2-3 times sometimes if they were varnished really bad to make sure I got all of the gunk out.

sounds like you are going to have to pull carbs off and clean jets also check tank and line for debries

I have a rayobi PBV30A petrol trimmer and it keeps dying once you increase the throttle speed runs on idle.