1996 KQ won't idle
 

Guys, I have a 1996 Suzuki King Quad 300. I let it sit up over last winter and I can't get it to idle when hot. It does fine before it heats up, but when it get warm, it smokes and will not idle. It also runs a little rough and is hard to restart. I took apart the carb and cleaned it. I also disassembled the fuel cock and cleaned the screens. Still didn't help it. I need help!

What color smoke? Will it run with the choke on?

I have the exact same atv as you and I have replaced rings, rectifier/regulator, cdi box, air filter, spark plug, new oil filter, new oil, and cleaned whole carb twice and new gas twice with seafoam both times and still can't get mine running right. Mine blows a lot of white smoke even before I put seafoam in it, and mine has a lot of trouble in the low throttle end or whenever I slow down it tries to die on me when I'm shifting down into lower gears coming to a stop unless I give it at least half throttle. Your problem could be any of these things like mine, or just simply your carb needs to be rebuilt if the jets or anything are messed up. I think my problem is simply the valves need to be adjusted as I couldn't get mine started the other day and I drained the battery while trying to do it with the electric start because it was like 20 degrees here in Texas. Yes it does get cold here. It also has lots of excess air and has white smoke coming from my breather tube underneath my gear selection area. When I was trying to start it on that cold day it was hissing from the same spot because the air and smoke was spewing. Mine also runs a little rough too and gets very hot to the touch within a couple minutes or just idleing. Also does your's stay running say if you hold the throttle, if not it could have same problem as mine in the ignition system where I had to replace the rectifier/regulator as it wasn't getting rid of the excess voltage output and it was putting it into my battery while running and screwing with the ignition system. If I was you I would first probably check voltage at the battery while running and see if it's over say 15 volts (mine was at 18.1 volts which was very high), if that's good then it could maybe be your float is sticking in the carb or valves unadjusted I would think as it won't run right probably like mine right now.

White smoke. Will not idle with choke on. It's kinda weird. It will idle OK while cold, but as soon as it starts warming up, it shuts off and is hard to start.

White smoke is excess gas or possible water in gas tank or mixed with gas. If your spark plug is fouled and covered in black sooty material like mine does then more than likely carb is letting too much gas into cylinder head. Mine hasn't been hard to start after its shut off before so I've no idea on that.