First 2-stroke. Now to jetting!

[Pygmygod]

Hi All, I've owned a Yamaha wr250f 4-stroke for 5 years.
Have recently bought my first ever 2-stroke, a 2007 EC200.

The bike came with an oversized tank so I assumed the jetting was a bit rich otherwise why would you put the big tank on, unless you're doing mammoth rides.

The jetting currently in the bike is:

Slide: 6
Idle Jet: 50
Main Jet: 178
Needle: NBHW
Clip: 2
Air Screw: 1

From the reading through some of the posts on here, the 50 pilot jet is probably far too rich.

I am also thinking the Air-Screw may need to be wound out half a turn as only 1 turn out is a richer mix, right?

It had a fair amount of spooge coming out the exhaust port as it needs new exhaust o-rings.

Previous owner was using Penrite Semi-Syn oil at 50:1.

Altitude around here is about 450mtr above sea level.
Riding temp ranges from 10C to 28C.

Considering this is my first ever 2-stroke, is the rest of the 'tuning' done by how it feels at each particular throttle%?
Will it be bit hard to determine since it's my first 2-stroke or is it easy-ish to just listen to the way the motor sounds to tell that it's off?

Thanks!