Zongshen GY200 help needed badly...screaming idle

[Asher]

g'day guys...i have a brand new zongshen GY200 road/trail...
when it starts the idle is incredibly high, and the idle screw and the throttle cable is NOT the problem...
what could possible be causing this?
ive read other people have had this exact problem, and was wonderign how i can go about this?

thanks a heap

[Reveeen]

the idle screw and the throttle cable is NOT the problem...

If the idle screw (not to be confused with the mixture screw) is having no effect, and there is plenty of slack in the throttle cable (enough to let the butterfly/slide close), then you have to start looking for a vacuum leak. How you do this is up to you, I prefer the non-flammable options (WD40?), checking the seal at the carb, and at the head. If it appears to be sealing, check the rubber intake manifold for cracks, and remove the carb to verify it is in fact closing. Sometimes a tight intake valve, combined with a mixture screw tweak (to compensate) will throw the idle speed, but the engine won't rev cleanly if this is the case (especially warm).

[MrJ]

It might be the carb slide is inserted 180 degrees incorrect. Carb slides have two notches in the side of them one long one and one short one. Remove the top of the carb where the throttle cable goes in, it just unscrews. Pull out the cable and the carb slide will be attached to it. Examine the carb slide. The carb slide is the round barrel thing with slots cut in the side of it. Examine inside the carb where the slide goes into the carb body, you will see two tits sticking out. One is higher than the other insure you put the carb slide into the carb so that the long slot aligns with the highest tit boobie . Sorry couldnt help but have a little fun with the words.

[Asher]

oh ok, ill check that out on friday, its nto with me at the moment...

what if there is a leak somewhere? how do i go about it?

also, what am i looking for by spraying WD40 around it?

its just i never leave it on, its so high its actually painful to listen to, as i know it isnt warmed up, and turn it off as its causign damage...

also, is it worth just getting rid of that carb, and putting on a 30mm mikuni?

and if i do this, what other mods do i have to do, and can i connect the mikuni carb to the airbox i have on it, or can i only use a pod filter?

thanks

[davidsonsgccc]

hy my intake flange split within the first 2 months of owning my bike.
it had a really high idle like you are describing. if there isnt any warranty on the bike i would suggest going to the local yamaha shop and see if they can match it up. i was told the yamaha has better quality rubber.
mine came from a mechanic who had it in his box however he couldnt remember what type of yamaha it came off of.

if this isnt the problem i would check the slide like mentioned earlier maybe trash is preventing it from closing all the way. make sure the choke is closed all the way it will cause high idle on a cold engine. finally you might make sure the mixture screw isnt turned out to far it is usually
2 to 2 1/4 turns out. dont over tighten when turning screw in only slightly bottom out or you may damage seat.

i dont know if any of this will help but maybe it will give you places to look .
shawn

[Reveeen]

what am i looking for by spraying WD40 around it?

By filling the vacuum leak it will affect how the thing is running.

This thread may be of some interest:

http://www.chinariders.net/modules.p...ewtopic&t=8711

(clearly showing ANYTHING is possible)

The rubber intake manifolds are also known to crack.

Something else to check is the flatness of the flanges (when/if you take it apart) I *really* hate flange mount carbs.

putting on a 30mm mikuni

Long haul/short haul? Short haul: flange mount 30mm mikuni. Long haul: proper spigot mount Mikuni manifold and Mikuni.

You kinda takes your chances if the stock air box will fit (probably a uni-filter is the best option as it will not leave you scrambling for an air filter in the future, just don't forget the oil!)

[Weldangrind]

X2 on the Uni being the best option. It's a lifetime filter, as long as you clean and oil it regularly and don't tear it.

Maybe you have a mismatch between the carb and the intake, like another member reported. His ran lean as a result, and I believe that a 30mm carb will solve his issue.