ATV

have you left anything inside.

are the valves set correctly.

now youve improved the compression the little or big ends would be under more presure when fuel ignites.

What parts were replaced in your rebuild?

Did you measure the piston to cylinder wall clearance?

The specs I found for the model you called out (Blaster) say it's a two stroke. There's not much to replace save piston and rings. The most common reason for the knock; to me, would be the possibility that a piston ring was broken during reassembly and went unnoticed.

If the wrist pin wasn't replaced and a new piston installed there may be excessive play there that could cause a knock. The last thing I can think of is excessive clearance between cylinder and piston.

Not to be a jerk, but you should have posted this in Automotive. There are more people lurking there that are more interested in engines and mechanicing.

1. Did it have the knock before? Is that why you rebuilt it?

2. Is this your first rebuild?

3. Did you align the rings properly?

4. Not enough information to give any real advice.

5. We don't read minds.