Picked up this dazon stinger 50 4 stoke 50cc quad. Guy said it was running fine then it starter acting up. Whatever that means...lol. Problem it's having is...it will start if throttle is at least 1/2 pressed. Then it only barely idles. Until you let off throttle then it dies.
Things I have done.
Disconnected the remote control kill switched.( just unplugged it from harness).
Changed spark plug.
Took apart carb and cleaned internal parts, jets, ect.
Checked for loose wiring.
Took electronic choke off and unplugged while it was running.
But still no change. Not sure where to look next.
New carb? New cdi box? Or am I missing a safety feature somewhere? It acts like its a safety feature. There is no throttle response. Just a steady slow idle that dosent change no matter what. Spray starting fluid in carb while running, just kills it. Spray starting fluid directly in head, nothing.

Any help would be awesome! Thanks.

 

You can't just remove the electric choke, or disconnect it, as it works by alternator power gradually making it turn off when running. If you disconnect it, the choke won't turn off. If you remove it, air gets down the mounting hole and weakens the mixture.

Adjust the valves, unlikely to be your problem, but need checking anyway. My guess is you haven't got all those tiny holes clean in the carb, double check it, and look through the jets to make sure they are clean. By the way, it won't be a GY6 engine at 50cc, probably an E22 clone.

 

Thanks for your reply.
I cleaned carb pretty well. Went through all those little hose with a torch tip cleaners. And blew compressed air and soaked all parts.
Ran exactly the same with elec choke installed and plugged in, and unplugged, and taking completely off, and with my finger covering choke hole.
I noticed my slide on carb is not moving while running or while pressing throttle. I assume it's vaccum activated.
My intake there is a vaccum coming off of it with a 2" hose connected to nothing. Can't seem to figure out where that might go. Carb has no spot for it to go, nor does the fuel pitcock. Not sure if that's were my problem lyes.
No idea what other guy had done to this, starting look like it never was running like he said.

 

Ok. Benched checked the slide in carb to make sure it was sucking.
Benched checked the elec choke. Working.
Retimmed the cam to flywheel.
Adjust valves.
Pored gas down cylinder, no combustion.
135lbs of compression
Plenty of spark
Still only barely idle at 1/2to3/4 throttle.
Gonna order new carb and cdi, just to scratch that off the list.
Don't really know where to go from here. Anybody help? I would be truely be greatfull.

 

I think your going to resolve this with the new carb your getting, cdi sounds fine from your symptoms. I've had a bad rectifier do strange running issues as well.

Just install the new carb and report back.

 

Will do mpdano. Hope that's what it is. Parts are super cheap for these Chinese quads. I don't know my way around 4 stroke engines. But this is educating me on them. Just the knowledge am gaining is worth what little money am waisting on it. Rectifier will be next on the list if this fails...lol.

 

It was a combination of two things.
1). Woodruff key sheared. Was way out of time.
2). It deff needed a new carb.
Thanks again for the help!

 

Ah yes, the dreaded key. Glad your sorted now.