I am possibly going to look at a little GasGas txt 2000 50cc twist and go for for my lad. Apparently it did run but know the guy can’t get it started after it’s been sat for a while. What sort of psi should I be looking at on a compression test? Obvs it will be cold too, also do you test with throttle wide open the same as we do on 4 stokes? 

Im not an expert on these but i remember one person trying to find engine parts for one a few years back nd they were like hens teeth. Worth a punt i guess if it doesnt need work from the outset