How to adjust richness of 2 stroke? stuttering bike? running very rough?

hey guys i have a 1983 kawi KE100 great little bike (when it runs). so its been running a little rough lately, and the most obvious thing that has gone bad are the plugs. but lets talk about whats going on with the bike first.



it %26quot;stutters%26quot; and %26quot;sputters%26quot; and sometimes it will leap forward, it won't exceed 22 mph and can not hit the rev limiter no matter what. its also very hard to start. i cleaned the carb twice. and all the filters and checked all the major lines. i also took the oil tank right out and tried premixing it! nothing. its like this all the time. although lately it would only accelerate in lower rpm, but still not fixed.



but anyway the main thing that i see is that it runs a ton better when you put a new plug in it (not perfect though still sputters). but it fouls dark black (oil?) a little later and that later has kept getting sooner and sooner (a few blocks...).



so i was told by multiple people that i was running to rich. but only recently i heard someone mention that you could adjust the richness of it somehow. any idea what this could be? is it a screw? also am i on the wrong track? i will get a compression meter soon and check that. but i think this might be a lot of it.



Thanks in advance!How to adjust richness of 2 stroke? stuttering bike? running very rough?On the body of the carb there will be a screw(usually brass).Screw it in clockwise til it lightly seats.Don't screw it in too tight as it will damage the tip.Then screw it out 1 1/2 turns.Start the bike.For the following adjustments go 1/4 turn at a time giving the bike about 15 seconds between each adjustment to react to the new setting.Start screwing the screw out(richer) 1/4 turn at a time til the engine starts to stumble from being too rich.Then counting the number of turns you make screw the screw back in 1/4 turn at a time(leaner) til the engine speeds up and dies from being too lean. Stop there.Now screw the screw back out half the number of turns you screwed it in.For example if you screwed it in 3 turns you would screw it back out 1 1/2 turns.It should be very close to being right.Adjust the idle and ride it.If need be fine tune the adjustment richer or leaner 1/4 turn at a time riding the bike between each adjustment.