good or bad?

I've looked and YZ250's sale high, don't remember seeing one for under $1000 since I've owned the Blasters. I don't know what it's worth but, to me, if the engine is strong and the swap work looks well done I would say that the price is a reasonable starting place. If the engine and work is good, the quad is just started. It needs wheels, tires, brakes, A arms, swing arm, shocks and probably all new bearings and better silencer to utilize all the power the YZ engine is making. Realistically, figure spending twice the asking price to match the rest of the quad to that engine.
 
The exhaust is fine the guy welded a extension in there so it would fit without cutting the frame and the carb looks like it has a ballon for an overflow tube
 
Thats the worst spot to do any modifications to a pipe.I would half to look at the pic again but it looks like a peice of shi$?.Its a good motor but who knows the condition of it with the lack of experience in throwing it togeather.I would say 1000 but this includes the cost of you having to rebuild the motor so minuse rebuild cost and thats what its worth.There is not much you can do with the motor as porting is right on from factory all you can do is clean it up and pipe it.I would throw that motor in my blaster in a heart beat as I am always going for another gear thats not there on this little think lol.