true, a top end does last longer on a four strokeI can only speak from my own experience, and I have had several 2 strokes that seemed to run hotter than the 4 stroke I had. The point is a 4 stroke will run longer without a rebuild mainly due to the not so great lubrication of a 2 stroke. And this lack of lube along with the constant fire burning up top can cause hot spots throughout the motor. And while I cant say anything about how well they disperse heat at low speed as I dont do much low speed riding. I will say that low speeds tend to lead to fouled plugs.
Both The 2 and 4 strokes should prove to be plenty reliable provided they are properly maintained. The 2 stroke just requires a little more in depth maintenance like rings and pistons where the 4 stroke needs oil changes and oil filters.
But this doesn't matter anyway. He's asking about a blasty and a shee.
As far as which is better I would say if you want all out speed get a shee if you want something light and easy on gas get a blasty.
but that is made up for on how much easier it is to do on yourself and on your wallet on the two stroke.
the four stroke is still more likely to break down than the 2, id still rather have a four stroke, but you get my point.
both four and two strokes foul plugs, its a fact, the two stroke is only more likely because some people cant jet worth a damn, which more likely causes fouled plugs on 2 strokes than 4's
i had a 3 year plug in my rm.