Coasting Enricher (CG125)

[CG125]

A little confused. i have a carb for my CG125 similar to the one shown in this picture. Now i want to ask a noob question plz, that these two golden pipes shown beneath the butter fly are these part of coasting enrichment circuit or just air bleeds ? What's the difference b/w these two terminologies (Coasting enrichment and air bleeds).

I heard that popping on deceleration is due to more air flowing in coasting enrichment circuit due to a faulty diaphragm ? Does this carb exhibit such function ?

If these are airbleeds tham popping on decel can be a result of these allowing more air to pass resulting in lean mixture ?

Plz a detailed reply will be much appreciated.
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If you ride like there's no tomorrow there won't be

[stinkwheel]

They are accessory jets which alter the fuelling at specific throttle openings. One is probably involved with the choke to allow fuel and air through when the choke butterfly is closed.

A coaster enricher is usually a small flap valve under a metal cover mounted on the side of a carb that allows the carb slide to lift on a closed throttle and I've only seen them on CV carbs fitted to big singles (those are not CV carbs, they are slide carbs).

Popping on the overrun is usually due to an air leak in the exhaust system. So check for holes then check for gas escaping when you revc the engine by holding your hand near any joints, especially where it attaches to the cylinder head and blipping the throttle (obviously being aware that you'll burn yourself if you touch it). You should feel any escaping gas blowing against your hand. Alternatively, you can sometimes see the gas escaping when you first start up on a cold, misty morning.

Next most common cause would be an inlet manifold air leak. Check by warming up the bike and, with it sat at idle, spray WD40 over the inlet manifold (where the carb meets the engine). If the revs increase, you have an air leak.

Next most common cause is people inexpertly fiddling with the airbox and/or exhaust system in an attempt to "tune" their bike and upsetting the fuel:air mix.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[CG125]

I have checked for all the leaks and there seems to be none.

However i found this in the following link

""Air-Cut Valve

An air-cut valve is used to prevent popping in the exhaust system during deceleration. The valve enriches the air/fuel mixture during deceleration. A diaphragm in the air cut valve is activated whenever high manifold vacuum is present, such as during deceleration. The movement of the diaphragm causes a partial blockage of the air bleed system in the low speed circuit. This reduces the aeration to the low speed jet which creates a richer mixture. The air-cut valve is factory pre-set and should not be altered. It may have to be replaced eventually, because the rubber diaphragm in the valve may deteriorate over time. If the diaphragm is deteriorating, you may notice leanness or a popping in the exhaust during deceleration."

https://www.4strokes.com/technical/carb-overview/

Now the only doubt i have is whether my carb contains this air cut valve or not, It is of Keihin 4 stroke slide type (pic posted in first post) but this diaphragm mechanism is installed inside the body of the carb.
____________________
If you ride like there's no tomorrow there won't be

[stinkwheel]

I've never seen one on a 125, they fit them to big dirt bikes which are often run for long periods on a fully closed throttle when descending steep gradients. My KLE500 had them.

I'm 99% sure a CG125 doesn't have one (in that I have seen several CG125 carburettors and they did not have a coaster enricher. But am not ruling out the tiny possability that they might have fitted one on some obscure model).

This is what a coaster enricher valve looks like:
https://i87.photobucket.com/albums/k154/HDI_IA/CoastValveShimming.jpg
Popping on the overrun on a CG125 is almost certainly an air leak somewhere. I will repeat, almost always in the exhaust system.

Another thng to check is that your sparkplug hasn't come loose.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.