Another hidden restriction by Kymco....

[Peters]

asources, you more than likely have this(black Collet) in your air box lid. Like I said it is in the air box lid. Remove it and look in the hole on the bottom(where the air comes in to the lid). You'll see a rubber tube. You can remove it with a little bit of twisting and pulling. You'll get a lot more air to your engine after that. You may have to mess with your idle a little after(no big deal).

[asources]

Great got it ... but ... power change all the time ...


Where is this %/$%/$%/ mixture screw ... will have to play with it until i change de main jet ...

I have a people s 50 4T 2009 ... picture of it ??

Stefan

[Peters]

Yes more air flow is more power all the time

Asources, don't get frustrated there is typically only two external screws that control the way the carb functions. One is the idle speed the other is the idle mixture. THATS IT. Im pretty sure 99% of the time the idle speed screw is larger than the mix screw. On my 2 stroke people the mix screw is on a slight incline(angle) and the idle screw is perpendicular. Yours is 4 stroke so it could be different.

[Peters]

Tighten (do-up) the mixture screw, you let in less air and a leaner mixture will result.
Loosen (undo) the mixture screw, you let in more air and the mixture will become richer.

ianmac, you are correct. The quote above is somewhat incorrect. Clockwise is less air and counter clockwise is more air but is also incorrect because Less air equals rich. More air equals lean. It's just common sense people.

[asources]

Yes more air flow is more power all the time

Asources, don't get frustrated there is typically only two external screws that control the way the carb functions. One is the idle speed the other is the idle mixture. THATS IT. Im pretty sure 99% of the time the idle speed screw is larger than the mix screw. On my 2 stroke people the mix screw is on a slight incline(angle) and the idle screw is perpendicular. Yours is 4 stroke so it could be different.

Thanks ... but where are those screws ... i have to look from the side of the pipe pr the sire of the air box ...

Do you have a picture of it ?

Stefan

[ianmac]

Those are just IDLE mixture screws, they have nothing to do with the amount of air/fuel that is going into the carb when you are riding the throttle
You are going to need a new main jet.

[Peters]

No pics sorry. Screws are on the air box side of of the bike. There is probably a rubber shroud around the carb. Usually there is a small hole in the shroud to access the idle speed screw.

[wordslinger]

..old post i ran across...

..doesn't the mix screw adjust fuel delivery, not air during idle?

..if so, then clockwise would create a leaner fuel mix due to the restriction of fuel, not an increase in air..

[Peters]

Ok, did a little research and found a good resource. Check out the link.

http://www.mypage.tsn.cc/rdd/TT/contents/CARB/dellorto/dellorto_3_4.html

Apparently it can work both ways, just depends on the carb. An air-adjusting screw is always usually upstream from the slide. A mix-adjusting screw is always usually downstream from the slide.

[wordslinger]

..yeah, and that is a excellent link btw....

..judging from the location of the screw on these kymcos, i'd say it adjusts fuel delivery...

[Peters]

Yep, my stock ppl carb and my dellorto both have adjustment screws downstream. So they would be fuel adjustment not air. 

[baddi]

Here are an almost complete walkthrough on the Constant Velocity Karburator (refered to as CVK), which is on the 4-stroke engine. The link i have given you is translated by google translate from danish to english, so translation might not be flawless.