welcome HyperMotard
I guess your talking about one of these bikes
Zuma XB33 140cc DirtBike
I have not had much to do with fitment of tyres on 14" rims, however I would think the principle stays pretty much the same. Normally 150 tyres want something like a 4.25" wide rim so your 3" rim will pinch the tyre a fair bit, not to mention that you most likely will not have the clearance in your swingarm.
If you have enough clearance the tyre will physically fit and will work in a fashion tho, just means that you would probably get better traction off a smaller tyre, don't forget that your engine has to turn the wheel, bigger / heavier wheel = less acceleration