upgrades

When I built my bike I took advice I learned from this forum and I broke my engine in slowly and I ran it thick @ 20:1 for about 4 - 5 GL of gas until it really opened up. I was told I would know when it happened and it was clear...now I run it @ about 36:1 I found that it runs best at that mix...

so ive burnt though almost 12 lt of fuel i've been nice and only opened her up once... so im starting to think about upgrades and aftermarket part?? so here is my list of what i want to do 1. change the spark plug to and NGK either B5 or B6 (not sure with is better ive read it really depends...

I am new to motorized biking, What are the best ways to increase my speed i have a grubee skyhawk gt5 with a cns carburator? I also have a boost kit (not installed yet) but i did install a 36 tooth sproket. usflgusflg.xx. Tank you so much, any response is apreciated.