Noob here! - Yamaha Aerox YQ50 Problem

hello everybody

Im new to this forum, names Evian from the UK

I just completed my CBT and just got my first moped, its a Yamaha Aerox YQ 50 2006

I am having some problems with it and want to sort it out before i tax and insure it

Is it ok to ask here? or do i need to make a thread elsewhere on the forum?

Incase it is alright here, this is the problem:

I start the bike, it runs low revs then after a few seconds (and a spot of throttle) build up to normal revs, the bike pulls off and rides, but as soon as i slow down or stop using the throttle the bikes wants to / most of the time does, cut out. Then it will not start again for a good while, maybe 20 minutes. Then it will start again and do the same thing!?

also the watercooling pipes near the engine were leaking but i have sinced flushed the system fixed them with new clamps and put some new coolant in, so i dont think it will be a overheating issue? really need advice here

I have checked sparkplug (working). I have checked compression with my finger not a tool it seems ok (i fit new piston rings as soon as i bought it as it was a non runner, wouldnt start at all) and ive checked fuel seems to be coming into the carb without an issue

It came with custom 17.5mm Carb installed, and powerpipe by Giannelli (carbon fibre bit on it) not sure what model it is!. Also it came with new Stage6 70 streetrace kit in box which i have not installed as i read up you need to buy a (performance) crankshaft to run it aswell, can someone advise a good one under £100 that will fit my bike?

Thanks so much for any help you can provide!