CG125es

[Indi5245]

Hi,I have a CG125ES project bike,bought as a runner but with what appears to be a carburation problem......it will not run ,even when warmed up,without the choke partly on! As soon as I shut the choke off the engine dies ! Have tried adjusting the pilot screw and tickover but as soon as I close the choke,she stalls. Even trying to get a constant tickover high or low is impossible,the revs rise and then fall! This bike is also fitted with a secondary air supply system/valve (PAIR)......wondered if this could be the problem!? Any help would be greatly appreciated

[Stu]

Hi and welcome to the forum

First I would strip and clean the carb and put everything back to stock settings also check the air filter to make sure its not clogged

The PAIR system will not affect it in anyway

[Indi5245]

Hi and thank you.

I have stripped and cleaned the carb and checked air filter and hoses.

I am using a Haynes manual , but where it gives settings for earlier model carbs, there is N/A for needle clip,pilot screw and float height settings !!!

[savo318]

Try HondaCG125.awardspace.com

This is a site dedicated to all Honda cgs

This is where I eventually found the settings for my carb. Plus other answers.

[RantMachine]

+1 for the awardspace site, it's amazing.

[Indi5245]

Thank you ,I will give that a try

[fastbob]

I don't know about the ES model specifically, I've only re built Jap and Brazilian CGs but I do know that CGs are extremely sensitive to changes to the airbox . On Brazilian models there is an insignificant bit of plastic that forms a sort of shield around the scoop on the airbox. Leave this off and the bike runs rough except on a bit of choke. Hard to believe but true. On very early Jap models it was made of metal and was actually part of the seat base. Have a look at the parts diagrams if you can it might be as simple as that. Pic to follow , I've got one in my scrap collection somewhere.

[Stu]

I don't know about the ES model specifically, I've only re built Jap and Brazilian CGs but I do know that CGs are extremely sensitive to changes to the airbox . On Brazilian models there is an insignificant bit of plastic that forms a sort of shield around the scoop on the airbox. Leave this off and the bike runs rough except on a bit of choke. Hard to believe but true. On very early Jap models it was made of metal and was actually part of the seat base. Have a look at the parts diagrams if you can it might be as simple as that. Pic to follow , I've got one in my scrap collection somewhere.

 

Thats not hard to believe to be honest

It means its restricting the air flow and removing it is allowing it to breath better but the jetting will be all wrong

Just shows how sensitive these little bikes can be to what we would think is a small change or an insignificant part

You have just highlighted what a lot of people do though....oh whats this little bit of plastic? I don't need that....throws in the bin then they have one crap running bike and they don't know why