Re: just starting
Welcome to the forum. We're glad you've joined the fun.
As for "screaming", are you referring to the high RPM of the engine at 30mph? If this is the case you might want to explore a smaller rear sprocket. It will impact your low end pulling power a little but the engine won't be revving as high at any given speed.
You didn't say what rear sprocket you currently have but many kits come with a 44T. Dropping that to a 40 or even a 36 tooth count will help with that "screaming".
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"