Just recieved some replacement stock helimax woodies for MX 400 pro and they are heavier than the orignals. The orignal factory blades came partially hollowed out. Anyone else see this? Where can I get those light ones again?

Yep, I got the same thing for mine. It made the heli a lot more responsive. I was worried about those hollowed out blades. They flex way to much. Maybe Tower Hobbies has the hollow ones.

Bob

Try the TRex yellow glass fiber blades. They're very good for learning on, though they suck for aerobatics.