Zongshen ZS250GS 06

Hey guys I just bought a Zongshen ZS250GS and i also got a scorpion aftermarket exhaust to put on. the only thing is I know that I have to rejet the carburator but I have no clue where to buy a rejetting package or what size should I get, I don't even know what size is the stock main jet... Can somebody help me pliiiizzzz
Thanks :D

[FastDoc]

Welcome to the forum.

I believe we are the only Zong Sportbike owners, and mine is in pieces all over the shop waiting for parts I hope will fix it.

I don't know the answer to your question. Best bet would be to look at the numbers on the jet with a magnifying glass.

You may get some info off this particular Zong site:

http://zongshenforum.com/forum/index.php?board=5.0

Bill

hey bro, thanks for the reply, I went on the link and posted something too, hopefully somebody has tryed to do the same thing to his 250 and would be able to help me out will see. I just don't want to spen 100 dollars on jets to experiment and see wich one is better :P too lazy for that jejeje

[Reveeen]

hey bro, thanks for the reply, I went on the link and posted something too, hopefully somebody has tried to do the same thing to his 250 and would be able to help me out will see. I just don't want to spend 100 dollars on jets to experiment and see which one is better :P too lazy for that jejeje

You will end up "fooling" with jets anyway!
Unless you have someone with:
1) the same bike
2) the same pipe
3) the same air box
4) at the same elevation above sea level
5) at the same temperature

Their recommendation will mean nothing but a starting point for your own "tuning". In temperature changes between spring-summer-fall I see up to a 10 number spread in "ideal" jetting here.

[Weldangrind]

Also, jets aren't very costly. You can make several changes for a modest amount of money.

allright the I guess I'll have to get my hands dirty :P by the way any idea what site sell the jets I need for this bike ? any models in particular ? I imagine the has to be diferent kinds of jets for different kinds of carburators right ? or is it the same design of jets for all the carbs ?

[SpudRider]

allright the I guess I'll have to get my hands dirty :P by the way any idea what site sell the jets I need for this bike ? any models in particular ? I imagine the has to be diferent kinds of jets for different kinds of carburators right ? or is it the same design of jets for all the carbs ?
Welcome to these forums, CG; we are very glad you joined us! :) Also, welcome to The Cult of the Zong. Reistance was futile. You have been assimilated! :lol:

http://i442.photobucket.com/albums/qq146/spudrider/20K%20Loop%20to%20Malad/resistanceisfutile.gif

Your ZS250GS sportbike should be equipped with a Teikei MV30, constant velocity carburetor. My Zongshen 200GY-2, dual sport motorcycle employs the slightly smaller, Teikei MV28, constant velocity carburetor, which is virtually identical to the Teikei MV28 carburetor employed by the 2010, Yamaha TW200 motorcycle. ;) You can learn a lot about your bike's carburetor by reading the appropriate threads in the Zong Sticky, located at the top of the Dual Sport Forum. :)

http://www.chinariders.net/modules.php?name=Forums&file=viewtopic&t=8673

If you wish to change jets on your TK MV30 carburetor, you have several choices. Teikei carburetor main jets are sold at MotorcycleCarbs.com, but they are fairly expensive at a current price of $7.95 per jet.

http://www.motorcyclecarbs.com/Teikei_Large_Main_Jet_C825.cfm

As with many members of the Yamaha TW200 forum, I prefer to use Mikuni series N102/221, small, round main jets. The thread on these Mikuni jets is slightly different from the Teikei jets, but the Mikuni jets still fit pretty well. ;) The Mikuni jets are more widely available than the Teikei jets, and are much less expensive. The current price for N102/221, Mikuni, main jets from Rocky Mountain ATV is $3.49 per jet.

http://www.rockymountainatvmc.com/allProductVehicles.do?&navType=type&page=all&webTypeId=80&navTitle=Intake%2FFuel&webCatId=16&prodFamilyId=25085

Mikuni carburetor jets employ a different sizing system from other manufacturers. However, through a process of trial and error, Yamaha TW200 owners have discovered that a size 132, Teikei, main jet is roughly equivalent to a size 130, Mikuni, main jet. If you decide to begin experimenting with different carburetor jets, you will find some general guidelines to help you contained in the following thread.

http://chinariders.net/modules.php?name=Forums&file=viewtopic&t=9165

Once again, welcome to The Cult of The Zong! :)

http://i442.photobucket.com/albums/qq146/spudrider/20K%20Loop%20to%20Malad/Anim_resist.gif

Spud :)

Well I'm starting with the main jets next week.
Now I wanna change the tires I have on my GS250 cus they have an edge on the side and everytime I take a corner too fast they slip a little bit... So I checked online and the size of the rear tire is 140/70 R 17 , now anyone has ever tryed to fit a 160/60 R17 on it ? cus I found an Apexi and Michellin Pilot that I really like but that's the smallest size there is ...
Thanks :P

[SpudRider]

Well I'm starting with the main jets next week.
Now I wanna change the tires I have on my GS250 cus they have an edge on the side and everytime I take a corner too fast they slip a little bit... So I checked online and the size of the rear tire is 140/70 R 17 , now anyone has ever tryed to fit a 160/60 R17 on it ? cus I found an Apexi and Michellin Pilot that I really like but that's the smallest size there is ...
Thanks :P
I'm guessing the 160/60 R17 tire will fit, but there is only one way to know for sure. ;) Measure the clearance between your current tire and the drive chain. The 160mm tire will come 10mm closer to your chain guard, and your drive chain. If the wider tire slightly rubs your chain guard, you also have the option of either trimming, or removing the chain guard. ;)

Spud :)

[nukeman99]

CG,... ahhhhhhhh,.... so you( CURRENTLY )have a running zs250? Hmmm... wanna do me an Doc favor? Could you pull your spark plug out, ground it against the head or fins, and tell us what kind of spark you have when turning it over visually? Doc an i have very weak spark on our 250's , and i would like to know if yours indicates the same.? I know it would be hard to compare being ours cannot be at the same location, but it sure would be nice to know the difference between a zong running and a zong having spark issues. If thats the case.......
Well i appreciate your help and hope that you are able to do this favor for us. Thanks again man, Bobby

Hey bobby,
So I did what you asked me and my spark is pretty big BUT I bought this bike about a week ago and i think that the guy actually changed the CDI and the rectifier so that might be a reason why my spark is good.
And I wanted to ask also, nobody has a zs250gs running ??? Mine has a minor electrical problem, sometime it seams like the batterie is dead so I have to push start it. I'm thinking that it's either the stator or just the cable is peeled somewhere I still don't know.

[Weldangrind]

This reminds me of an old topic on the now-defunct Giovanni forum. A few members had a 250 atv that had a gear indicator malfunction, and it was the same cause in each case: the wires from the stator were trapped under the cover and needed to be re-routed.

I'm hopeful that you guys will soon find some minor issue that is common to your bikes.

[nukeman99]

Hey CG....thanks man....i really appreciate your help buddy!!! Now i know,..... that its not just me! lol Youre right weldangrind,..odd that 2 bikes have the same electrical issue..
Thanks for that info Wng,...now that u mention it..there must be a wire shafed somewhere i hope, maybe causing a weak fire. Could be the switch or tach being Doc has changed all 3 units out of his already.. I sure hope so. im ready to make a sinker out of it! Anyone live near a cliff?
I ..i did change the plug yesterday, but it was another used one...yeah yeah i know,..not gonna help. So i pulled the plug wire, took the plug out and held it against the cooling fins once more to do a test. Well believe it or not, when i hit the start button.. it was firing(weak) and then quit while turning the engine over. !! 8O figured maybe i lost the ground not holding the plug correctly. But i trieded it again and same thing......would fire (weak) of course, and somewhat intermitt this time....
It has to be a ground problem or a shafed wire,..it has to be!!!. \
Check this out........... Now i did gently pull the coil wire to the right side of the engine before testing it , underneath the tank ,. thinking it should be there instead of directly over top the head.? Maybe there may be something with the coil wire...?
Well since the night i got stranded ..rrrrrrrr..... and let it cool down ,brought it back to my shop here, i havent been able to get her to start up since then and thats why i decided to check the fire again.
But why would it fire up after shes cooled off/..or at least so i can put my hand on the left side cover without burning it,.mostly just warm to the touch..
Doc, hate to deny it,... but im catching up with you man.....or at least got one paddle in your boat? Yeah sucks!!!
Thanks fellows for all your info and support,,,you guys are great!!!!
Now if the Long-dong...i mean Zongshen was as awesome as you guys then we'd be firing on all 4cyl's? Wait a min, it only has 1 :(

[FastDoc]

I might have enough patience to look at it again today. First one to figure it out deserves a beer from the other! 8)

My plan for today is to isolate the kill wire on the CDI and cut it. If the problem has anything to do with the 'off' switch anywhere on the bike that should eliminate that circut and let the bike start. :?

I'm not optimistic though. I would think if there was a kill switch activated somewhere there would be ZERO spark, not a weak one. Who knows though. All the usual culprits have been addressed. :cry:

In my case it can't be a bad wire or chaffing. They are all new :cry:

Bill

well finally got the money to start experimenting with carburator jets, went online and found the mikuni ones but I just have no idea with what number to start, somebody has an idea ? I know that the carb is the same as the Yamaha TW200 so somebody knows what size is the jet on that one?
I would really apreciate it :)

PS: SpudRider, I sent you a couple pm but I've been reading on some posts that there a problem with the pm service, you tell me :)