Anyone know what this is??

Thats definately a old Yamaha Dirtbike engine. See how the clutch cover is oval like an egg? They only did that with bikes. The top end is also different. The head is smaller so that it would fit under a low tank. Who knows what it is. Or even the CC if he thinks that it's a Blaster motor. Could be a big bike, could be a dinker. You never know. And also, it needs parts and how are you supposed to get them if you don't know what the motor is. I say stand clear of this.
 
Same things I saw. Different clutch cover, stator cover and top end looked more squarish to me than a Blaster. Carb also looked like it was not as angled from the intake. I thought maybe and old DT or MX?