Huasheng choke/carb problems

[Ollie]

Hi guys, I have a relatively new Huasheng 49cc which had been working fine at first and I was very happy with it. Yesterday though, after a long stretch of full-throttle riding when I was late to work, it developed a weird problem.

When the engine is hot or cold, it won't start in either choke position. However, it will start if I twist the throttle half-open. If I then accelerate and open the choke, there is a short delay before it jerks into life with full force. With the choke open and no acceleration, it dies instantly.

I've tightened the bolts attaching the carb, cleaned the air filter, and tried adjusting the idle. I'm not sure what else to try, any ideas?

 

[bakaneko]

Mebe play around with the air mixture adjusting nut before trying anything too extensive.

 

[Tony72373]

My 53cc HS did something very close to your issue. I took carb apart and sprayed cleaner everywhere. Reassembled and it worked as new. Never saw any micro grit but I can only assume there was a small blockage somewhere.

 

[Ollie]

Thanks guys, I've got the day off tomorrow so I'll try adjusting the air mix and then disassemble and clean the carb if that doesn't work.

 

[Tony72373]

Also make sure fuel flows free from the tank to fuel filter and carb. You probably know this , but just covering the bases.

 

[Ollie]

I took the carb apart and cleaned everything, and also noticed that the air mix screw (the one with the spring) was so unscrewed that it was about to fall out.

Engine is getting fuel, and I tried starting it quickly in my apartment and after screwing the air mix screw fully in, it started first time with the choke closed and died the second I opened the choke.

I'll take it out to the street now and see if it'll run with the choke open after it's warmed up. Any idea what the right air mix setting is, or a good starting point?

 

[bakaneko]

I took the carb apart and cleaned everything, and also noticed that the air mix screw (the one with the spring) was so unscrewed that it was about to fall out.

Engine is getting fuel, and I tried starting it quickly in my apartment and after screwing the air mix screw fully in, it started first time with the choke closed and died the second I opened the choke.

I'll take it out to the street now and see if it'll run with the choke open after it's warmed up. Any idea what the right air mix setting is, or a good starting point?

See Trey's post. Be patience with toying around with the air mixture and idle screws to get it good.

https://motorbicycling.com/threads/adjusting-the-huasheng-142f-49cc-carburetor.41561/

 

[Ollie]

Problem solved! Yeah it was the air mix screw that must have undone itself from the vibration of high rpm. I'll see if I can find a stronger spring for it.

I screwed it in all the way, then unscrewed it 3.5 turns. It immediately began acting normally. Thanks for the help guys, I really appreciate it

 

[Tony72373]

Good to hear your back up and running.

 

[wilee60]

Hi guys, I have a relatively new Huasheng 49cc which had been working fine at first and I was very happy with it. Yesterday though, after a long stretch of full-throttle riding when I was late to work, it developed a weird problem.

When the engine is hot or cold, it won't start in either choke position. However, it will start if I twist the throttle half-open. If I then accelerate and open the choke, there is a short delay before it jerks into life with full force. With the choke open and no acceleration, it dies instantly.

I've tightened the bolts attaching the carb, cleaned the air filter, and tried adjusting the idle. I'm not sure what else to try, any ideas?

I had the same thing happen, it got worse eventually wouldn't start at all.
I replaced the ignition coil (very hard to find the right one for those 4-7g HS motors) and it started very strong right away. Check the spark to see if it's weak. Find out if you have a 142F or E type motor but it's still a pain unless you have the 4g it seems everyone has them, mine "was" a Ghost Racer 7g, it's now a Honda 50.