Vintage Dirt Bike Q & A

I've been restoring this for awhile know. I'm almost finished. I need some help with 2 things. The first is that the power band is'nt kicking in until 3/4 throttle. The top end was redown, so it sounds like a carb problem. What should I do to fix this? my only guess is moving the needle or changing jets. The next thing is the front forks. I checked the springs and chaged the fluid and it was great. know there is no rebound. they compress and stay compressed when standing over the bike pushing down. What can I try to fix this?