PDA

View Full Version : Cfmoto vnight carbureter adjustment


Engineern6719
03-23-2016, 09:36 PM
Wondering if somebody could give me some advice on carbureter adjustment.The idle RPM is outside specs and want to adjust it.There is only one adjustment screw and I don't know whether this is for idle speed or mixture.Also on the left handlebar is from what I presume is a choke lever connected to a cable running down to the carbureter as well as the throttle cable.Could somebody be able to explain how it works.Also would anybody have any idea what brand of carbureter it is?

humanbeing
03-23-2016, 10:21 PM
Don't know what's in ur bike...
Domestic official record http://www.vecc-mep.org.cn/static-web/index/ggxx/2012-35/OIII-MT1.pdf is Mikuni VM22 from Chengdu http://www.mikuni.co.jp/e/overseas/china.html | http://item.taobao.com/item.htm?id=520276978165

Engineern6719
03-24-2016, 08:31 AM
Don't know what's in ur bike...
Domestic official record http://www.vecc-mep.org.cn/static-web/index/ggxx/2012-35/OIII-MT1.pdf is Mikuni VM22 than made in Chengdu http://www.mikuni.co.jp/e/overseas/china.html | http://item.taobao.com/item.htm?id=520276978165

The one fitted to the bike is the same as on the taobao.com website.As you can see from the photos on that site it only has one adjustment screw.What I would ideally like is a shop manual which would tell me if it is for idle speed or mixture setting.

humanbeing
03-24-2016, 05:29 PM
Idle speed ONLY.
Air screw's position is as http://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Floncin-cub.blogspot.com%2F2014%2F01%2Fblog-post.html

Engineern6719
03-24-2016, 09:56 PM
Idle speed ONLY.
Air screw's position is as https://translate.google.com/translate?sl=ja&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Floncin-cub.blogspot.hk%2F2014%2F01%2Fblog-post.html

What would the method be for adjusting this air screw?

humanbeing
03-24-2016, 10:30 PM
What would the method be for adjusting this air screw?
http://translate.google.com/translate?hl=en&sl=zh&tl=en&u=http%3A%2F%2Fzhidao.baidu.com%2Fquestion%2F10707 3049.html
If too much hassle... Bin it & fit a Keihin clone is 1 of the quick chinese solution
---
Float height ??? series
http://translate.google.com/translate?hl=en&sl=zh&tl=en&u=http%3A%2F%2Ftieba.baidu.com%2Fp%2F3405033763 | http://translate.google.com/translate?hl=en&sl=zh-CN&tl=en&u=http%3A%2F%2Fwww.motorfans.com.cn%2Fthread-17775877-1-1.html

Engineern6719
03-25-2016, 04:43 PM
http://translate.google.com/translate?hl=en&sl=zh&tl=en&u=http%3A%2F%2Fzhidao.baidu.com%2Fquestion%2F10707 3049.html
If too much hassle... Bin it & fit a Keihin clone is 1 of the quick chinese solution
---
Float height ??? series
https://translate.google.com/translate?hl=en&sl=zh&tl=en&u=http%3A%2F%2Ftieba.baidu.com%2Fp%2F3405033763 | https://translate.google.com/translate?hl=en&sl=zh-CN&tl=en&u=http%3A%2F%2Fwww.motorfans.com.cn%2Fbbs%2Ft_1777 5877.htm

Sorry humanbeing but that doesn't seem to work at all on a IPad.

humanbeing
03-25-2016, 06:18 PM
http://zhidao.baidu.com/question/107073049.html [SAME vm22 but euro2 version]
Q:My Suzuki "GSX-3C" only one carburetor idle adjustment screw, no adjustment screws mixture...
A:GSX125-3C using a plunger type carburetor, which mixed gas adjustment screws are located directly below the front side, and close the intake hose between the carburetor and the engine ... concave, so only crawl under or removing the carburetor in order to see clearly Its adjustment method is screwed to the end and then back on 1.5 to 2.5 turn
===
2.25 was quoted in some Suzuki forum. If in doubt, search pit bike related in 'net will give u the idea...

Engineern6719
03-26-2016, 06:21 AM
http://zhidao.baidu.com/question/107073049.html [SAME vm22 but euro2 version]
Q:My Suzuki "GSX-3C" only one carburetor idle adjustment screw, no adjustment screws mixture...
A:GSX125-3C using a plunger type carburetor, which mixed gas adjustment screws are located directly below the front side, and close the intake hose between the carburetor and the engine ... concave, so only crawl under or removing the carburetor in order to see clearly Its adjustment method is screwed to the end and then back on 1.5 to 2.5 turn
===
2.25 was quoted in some Suzuki forum. If in doubt, search pit bike related in 'net will give u the idea...

Thanks mate shall look into it.I like to have an understanding how this carburetor works especially the choke system as all mine does is stall the engine when I use it.The manual I downloaded says not to use it above 68 degrees F.So that answered that query as it's above that temp here in Sydney.
Thanks again humanbeing for all your help.

humanbeing
03-27-2016, 12:44 AM
... I downloaded says not to use it above 68 degrees F...
Those thingy works on 1 of these principal... "Restricts airflow" https://en.wikipedia.org/wiki/Choke_valve#Automotive or "add extra fuel"...
HK, southern Guangdong had a few days <15ÂșC in a year only. I don't care which is which as long as it works [不管白貓黑貓,抓到老鼠就是好貓 | It doesn't matter a cat is black or white, as long as it catches mice] in cold days...

Engineern6719
03-27-2016, 09:51 PM
When I checked the air adjustment screw it appears to have worked its way out.There's a paint mark on the body of the carburetor and on the head of the adjustment screw and they don't line up.After screwing in the screw to align the two paint marks the engine idles (when hot) at 1500-1600 rpm plus the choke worked when starting it cold.