Bike cutting out

[hydroshok]

When I start my bike with the choke on and coast down the hill while it warms up; it will cut out and almost stall when I hit a bump or apply the brake. It is getting plenty of fuel and does not do this when warm. It is a 1994 oil cooled bike the PO hacked up into a streetfighter. I tried to fix everything I could see that was wrong with the bike. It runs great and I have no other issues with it. Any thoughts would be appreciated.