Engine Trouble 66cc/80cc Stock engine will not idle

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sh4d0wm4n42

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Hey guys, so I've been searching everywhere.... Here and YouTube. My problem is the engine will not idle at all. I've checked the slide in the carb and it's positioned properly. I can get the engine to run, but by the time it's running I'm about ready to pass out or puke my guts up. Even when the clutch is locked at half, it won't idle at a full stop just to warm up the engine. Bearing in mind this is my first build, it's fully stock. I've checked through the forums and tried other suggestions such as reseating the slide in the carb, adjusting clutch tension at the motor, but I cannot get it to idle to warm the engine up... And it's been like this for the 5 months that I have had it running.

I was living in the mountains, and even riding down hill it took 45 minutes to a hour to get the engine to kick over. Any help is appreciated... I'm going insane trying to figure this out.
 
if idle screw is all the way in, that usually means you are way too rich and dropping needle down should help

otherwise, I'd start with a compression test
 
Fuel, air, mixture, intake, compression, spark, exhaust...

In no particular order (start with whatever is easiest).
Check fuel flow from the hose by pulling it off the carb and draining fuel into a cup.
Check air flow through the filter by taking it off and blowing through it.
Check intake is sealed by spraying water or carb cleaner on it's welds and at the ends while the engine is running.
Check the a/f mixture by a quick look at the sparkplug colour.
Check the compression with a compression tester.
Check for strong consistent spark by holding the plug against the outside of the cylinder head.
Check exhaust is flowing by taking it off and blowing through it.
 
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Well in regards to the idle screw, I had read a post here for it saying to screw it all the way in, then to unscrew it 4 full 360 degree turns. So that's where its sitting at right now. The fuel flow is good, I had to drain the tank on Friday when we moved from Tennessee to Kentucky to avoid any leakage during the trip. Intake and exhaust have both been resealed due to blowing out the gallery's, so I've got brand new gaskets in.

Gonna check the air flow and spark plug in just a moment, and gonna check to see if the exhaust may be plugged. However I don't have a compression tester at the moment so that may be the only step I can't do at the moment. The part that's confusing me is that most posts I've seen have said to have the engine start up with the choke all the way up to start, then to pop the clutch to neutral to warm the engine up but doing so even a slight bit kills the engine instantly. I do have the kill switch disconnected at the moment, so I'm certain it's not that that's killing the engine.
 
Ok so I checked the exhaust and air filter, both are clear of any obstructions and debris. Air flows smoothly through both with minimal effort. Gonna try checking the slide again... Maybe I need to adjust the needle maybe?

Also, spark plug isn't drenched, but also not completely dry.
 
Took it for a test but I still have no idle... The slide it's positioned correctly and the c ring is on the middle slot on the needle... I'm so confused as to what is wrong. Checked with AutoZone nearby while I was over there, but they don't have a loaner compression tester anymore. I know it'll run, but it takes about 45 minutes to just kick in gear.
 
I would try the next notch up on the needle, lean it out a bit. If even a little choke kills the engine even when it's cold then it's running rich. Rich is good for break-in stage but it is probably just too much.

For me the second from top notch (with the stock jet) is plenty rich enough for break-in stage (though I did a few mods).
 
Gotcha thanks furry, I'll switch that out in the morning. Right now it's a bit too cold out to mess with it and I don't have anywhere heated to work on it. Really hoping something will work... It sucks having to put so much effort into trying to start it up and naming myself get sick over it.
 
idle screw must be set for proper idle speed (absolutely NO set number of turns) - get motor started and hold throttle to keep it running then turn screw in until it idles
 
Crassius, so I need to be moving while doing this? Cause I have no way to start the engine while standing still. I've tried to kick start it at a stand still, but when I do, the pedals won't move at all. It's almost as if the gears are locked if I'm not moving. Forward momentum is the only way I've been able to turn the engine over while riding. And mine doesn't have a pull start, although I've considered adding it on. Found the parts to do so for 15 bucks on Amazon.
 
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