Help with carburetor on Zongshen 125 - 18

**Donnelly** · 05-14-2015, 09:36 PM

Hi everyone. I must say I'm a bit stumped. I got a Zongshen LZX 125 - 18 and it had problems with starting and idling. It used to have to be revved to be kept running. I then cleaned the carburettors and now it over revs to about 4000RPM. No air leaks and idle screw all the way out. Can someone give me a bit of help on how to tune these carburettors properly and where on them do I adjust the mixture. I cant find any screws or anything as I know it was running too rich before from a sooty plug. Any help?
Thanks

**Zorge** · 05-15-2015, 08:51 AM

CV carbies?

**humanbeing** · 05-15-2015, 09:23 AM

http://www.joinbike.com/forum.php?mo...id=5091&page=1 That bike is a 4V Suzi clone.
The REAL one is using Mikuni BS26, don't know Zongshen is usung which ...

**Donnelly** · 05-15-2015, 10:50 AM

Originally Posted by humanbeing

http://www.joinbike.com/forum.php?mo...id=5091&page=1 That bike is a 4V Suzi clone.
The REAL one is using Mikuni BS26, don't know Zongshen is usung which ...

Its a mikuni carb that's on it, not sure what model. I don't normally touch carbs. I do electric's, make wiring looms and rebuild top ends also. I never had to touch a carb like this.

**Zorge** · 05-15-2015, 12:55 PM

Wait for a sec! You have carburetor (singular) or carburetors (plural)?

I ask you this, because there is one 125 cc "Zong", also LZX, with a twin cilinder engine, which is, if I'm not mistaken, clone of a "Honda" CB 125 T engine.

**Donnelly** · 05-15-2015, 01:57 PM

Originally Posted by Zorge

Wait for a sec! You have carburetor (singular) or carburetors (plural)?

I ask you this, because there is one 125 cc "Zong", also LZX, with a twin cilinder engine, which is, if I'm not mistaken, clone of a "Honda" CB 125 T engine.

I have the single carb model.

**Donnelly** · 05-15-2015, 06:02 PM

Picture of my carb.

This is where i can find the idle adjusment screw. It was turned down on the bike.

Inside of my carb bowl

Where the pilot jet goes. Do I have to adjust this? when i got the bike it was screwed all the way in so im confused?

Another screw on the outside of the carb. Think it is a air screw?

Can someone help me out with tuning this and what I need to do with it? I cleaned gunk out of the pilot ject but it was screwed all the way down so i dont know do i need to adjust this? And the only screws on the outside of the carb is the idle screw and what I think is a air screw (4th picture).
Thanks

**Zorge** · 05-15-2015, 08:10 PM

Oh, my! You too have "Acer" monitor.

About carbie: it is CV type, and you must to screw all the way both jets - no adjusting there. On a fourth pic is the screw you need. But before you start to adjust anything, disassemble carb, clean it and check is his diaphragm in one piece, is needle where it suppose to be, and also manifold between carb and motor head.

And then, screw No.4 pic screw to the end, and unscrew for a 1 1/2 turn, and after that (or even better - before), look on the Internet how to tune CV type carburetor (there are tons of pictorial, textual and video manuals on the subject) because my English is about to collapse... here and now.

**Donnelly** · 05-15-2015, 08:18 PM

Originally Posted by Zorge

Oh, my! You too have "Acer" monitor.

About carbie: it is CV type, and you must to screw all the way both jets - no adjusting there. On a fourth pic is the screw you need. But before you start to adjust anything, disassemble carb, clean it and check is his diaphragm in one piece, is needle where it suppose to be, and also manifold between carb and motor head.

And then, screw No.4 pic screw to the end, and unscrew for a 1 1/2 turn, and after that (or even better - before), look on the Internet how to tune CV type carburetor (there are tons of pictorial, textual and video manuals on the subject) because my English is about to collapse... here and now.

Thanks so much for the reply. You've helped me alot :D I shall let you know how things go. Thanks again ��