Re: 94 Johnson 50hp J50TLERE need HELP!!
Welcome to iboats.
Sounds like a classic case of clogged main jets, they are located in the very bottom of the float bowl behind the drain plugs and you will need a long skinny screw driver to get them out and it is best to sacrifice a screwdriver and grind it down till it just fits in the drain hole or you risk breaking off the ears on the jet.
Your engine has 3 sets of jets, idle-mid and high speed, the idles are on the top front, mids on the back top and high speed in the bottom of the float bowl.
You need to pull the carbs and one carb at a time remove and clean all the jets with a stranded copper wire that just fits the hole, keep the cover screw with the jet so you don't get them mixxed up and work on a newspaper so you don't get any new dirt on them.
Try this and see if it solves your problem and it is very bad for the engine to run it above 1500 rpm with no load on it.