206 Idle help

My son runs a red slide in his cadet class.

We have the float at .880/1.050 drop and the needle on position 2. The air bleed is a half turn out. With these settings it idles fine.

Issue is I want to run the air bleed at 1.5 turns out. When I try this I can’t get it to idle at all even turning the idle screw all the way in does nothing. I installed a new idle jet and it still won’t idle.

Any thoughts!?

Try needle position 3. Your float and drop seem reasonable.

How is it running on the track? Does the engine idle better when it gets hot?

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It’s fast on the track. I set my valves a little different this time. .006 intake and .002 exhaust. Could that be the reason for no idle?

Should I just tell him to idle it with his foot?

Needle position 3 does not change anything. Kart also pops when let off from full throttle. To rich Id assume!

Some folks will set the kart to not idle, personal preference/beliefs.

Could you possibly have an air leak? The rubber cover on the cable sheath at the top of the carb and/or the gasket between the cap and body are prime leak areas.

Check your carb again. Float measurement and jets. Something isnt right. It should idle all day long like that with in needle position 2/3. Is the cap tight? Leaving the cap loose to try to increase the slide opening will cause an air leak and he’s with the idle.

Cap is tight but cap gasket is old. I will put a new one on.

Your valve settings are not optimum in my opinion, but it shouldnt be different enough to cause an idle issue. Has he been in an on-track incident recently? Check the intake manifold is not bent and the gasket seal is tight. Also check your exhaust gasket. Folks often think the pop/crack when coming off throttle is rich, but it can just as easily be lean.

Whats your carb suggestions? Maybe I should try to add some fuel?

Idles now. Found a clogged idle jet and a bad gasket in the carb cap. But still a bad popping from exhaust.

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I’ve never really worried about the overrun popping. Generally I’ve found that it happens more so if the idle circuit is lean. The leaner mixture burns more slowly meaning more of the combustion is happening in the exhaust.

Is it popping when you let off the gas? If so then what James said is the case. Move the needle further out (4) and I bet it will go away. But like he said it’s not main concern. If it idles, doesn’t stall then you want to adjust everything to make more power…