I have a 99nighthawk motorcycle 250cc cbx. That stall when put in gear. I've disconnected the kjckstand witch but still stall when put in gear. Starts & runs fine while in nuetral can someone plz. help ?

if you have these things it should start. are the plugs getting wet this indicates fuel is getting to the cylinder and not just to the carb. you will have to check the carb it could be a dirt problem stopping the fuel getting to the cylinder. if all you did was change the plugs and this happened after you will have to go over every thing you did to make sure you didn`t forget something. have you re-installed the plug wires in the correct order.

try to bump start it , usual thing with motorcycle, is it electric start ? if so battery may not have enough ampage , so kick start or bump

Make sure all the letters and numbers on the plugs are exactly the same some plugs numbers and letters vary but still work, the way they are different is charge and heat settings some bikes work some dont, also make sure you use a torque wrench when tightening your plugs u can never be safe enough!

Your gear switch is bad, also check your clutch. It might not fully release or engage. Also check the clutch cable at the steering.

Pull the clutch lever in and see if there is any resistance. If it has little or no resistance at the lever, it has air in the line(if hydraulic) or the clutch cable needs adjustment. The clutches are probably not fully disengaging (dragging)which could be why it turns off when placed in gear.

Just a guess, but sometimes when a load is applied to some motors, if they stall or bog down, they probably need a valve adjustment.

You can't just unplug the kickstand switch, you have to put a jumper wire in making it think the switch is closed.

It maybe a safety switch in the clutch lever ?

sounds like the carb float tang is not set properly causing insufficient fuel to be in the bowl. i'd have a look at it and adjust as necessary.