New Zongshen RX3 (ZS250GY-3) Dual Sport

[SpudRider]

FTEY,

Thanks for posting the photographs of your KTN RS3. I see you got the stainless steel, exhaust header and the new headlight.

Did you get forks with rebound adjustment? Did you get a rear hub with a cushion drive? If you have time, please post photos of the left side of your rear wheel, and the tops of the forks.

[SpudRider]

Originally Posted by Wolftrax

This was what I was hoping for. Keeping the original and then build a 21" wheel from another hub. I'm tempted to do it my self but may take you up on your offer to build me one.

I have searched, but I can't find the RX3 front hub for sale. I wonder if the Zongshen ZS150GY-10 employs the same front hub? The hubs don't cost much, and the shipping weight is low.

Buchanan's custom spokes cost about $110, delivered. A 21-inch alloy rim costs about $100, delivered, from Rocky Mountain ATV/MC.

[Huck369]

Originally Posted by Louis Angel

Holly crap I want one of those Zongshen RX3 bikes!!!
Cant AFFORD it right now, so I don't feel the least bit bad about ordering the new Lancer today. BUT, I can already see that in my Garage in 3 years!!! WOW THAT IS AWESOME LOOKING!!!!!

I see you're in TN, depending on where in TN maybe you can come check out my Cyclone sometime after I get it home....

[thillskier]

Spud, thats really good of you to post up all that work for us. Thank you!
I would definitely want to add the 21" option at some time when budget allows, but would pay for the hub now if you do a GB or order them so you aren't out the $ for mine.
Please keep me posted and let me know when/if you go forward with this.

Also, I'd really like to go tubeless so a tubeless rim would be they wat to go for me. Wouldn't that lower unsprung weight also to eleminate the tube?
Probably will add the tubliss system on rear for a while, if that system works well. (or whatever is best easiest and reliable system. I like being able to air down and still run when in some offroad situations, also. Tubeless plugs and a compressor will take up less space than tubes and tools I'm thinking when riding out.

[thillskier]

I have a friend, from 40+ yrs ago, one of the best street and off road riders I ever saw ride. He rode a 500 Kawasaki triple in HS and raced mx for the regional Yamaha and Kawasaki teams back in the day.

He is a bit skeptical but I sent him links etc so it'll be interesting to see his comments after reading the tests and blog etc. AND riding my bike when I get it here also..

He's one of those guys who'd wheely by at 50+ mph on the Kawasaki, and I know the story is legit cause he passed me doing it. He's stand on the back passenger pegs and just wheely for 1/2 mile or so (it seemed!
Unreal..unreal he never had a serious crash on road, ever or me!! for that matter. Hope it stays tha way! hehe

[FTEY]

Originally Posted by SpudRider

FTEY,

Thanks for posting the photographs of your KTN RS3. I see you got the stainless steel, exhaust header and the new headlight.

Did you get forks with rebound adjustment? Did you get a rear hub with a cushion drive? If you have time, please post photos of the left side of your rear wheel, and the tops of the forks.

Not sure abt those. I will get more photos. Btw the malaysian version is on carb. Anyway, my cold start needs lots of time on the start button n throttle before it would get going. Is that normal or is it because the engine is still new?

[SpudRider]

Originally Posted by FTEY

Not sure abt those. I will get more photos. Btw the malaysian version is on carb. Anyway, my cold start needs lots of time on the start button n throttle before it would get going. Is that normal or is it because the engine is still new?

Please do post more photos.

Our bikes are fuel injected, and we haven't received them yet. Therefore, I don't know much about your carburetor. However, I think it's possible the pilot jet of your carburetor is a little too small. You might want to try the next largest size of pilot jet, and see if helps. You might also want to try adjusting the pilot mixture screw on the carburetor.

[thillskier]

With a thousand or more miles on it, the rings seat and tolerances tighten up a bit (in cylinder/combustion chamber area) which will allow a bit more vacuum and also resultant compression increases. Usually that will help atomize the fuel a bit better as it will have faster air moving through carb (and over fuel jets and fuel metering needle) giving you a bit more turbulence there in the carb and intake passages, which makes a more uniform air fuel ratio, burning more completely/easier ignition, more complete burn = faster warm ups and less stumbling, etc.
I generally wait to rejet carbs until after break in due to this situation.
Spuds ideas re fuel screw adjusting and other carb fettling is a good idea anytime, because its easily changable when/if other parameters in the engine change for whatever reason. (free flow exhaust, or air cleaner, egr and or cat converter removal, etc.)

[thillskier]

Oh, what a great thing those adjustable idle screws are (elsewhere) and used to be here in USA.
Most carbs (all I've ever seen in YEARS here in USA) on any engines bigger than 50cc (exempted engines), have the covers glued or otherwise attached permanently to the carbs so one cannot adjust the low speed (or high speeds) air mixtures! Thats supposedly for EPA, ut a stumbling stalling engine HAS to be putting out unburned HC's, in larger amounts, I'd think than if it was running correctly.
Thats why most engines are efi'ed today. The multihole injectors atomize fuel very well, and can then be run extremely lean, without issue. STarts cleanly, though the ecu allows a bit extra fuel until water temps get to operational temps. Thats also why efi'ed bikes get the terriffic mpg. 70 efi'ed vs 45-50 carbed (like KLx 250 Kawasaki (carbed) vs Yamaha or Honda 250 ds.(efi'ed)

[FTEY]

Originally Posted by thillskier

With a thousand or more miles on it, the rings seat and tolerances tighten up a bit (in cylinder/combustion chamber area) which will allow a bit more vacuum and also resultant compression increases. Usually that will help atomize the fuel a bit better as it will have faster air moving through carb (and over fuel jets and fuel metering needle) giving you a bit more turbulence there in the carb and intake passages, which makes a more uniform air fuel ratio, burning more completely/easier ignition, more complete burn = faster warm ups and less stumbling, etc.
I generally wait to rejet carbs until after break in due to this situation.
Spuds ideas re fuel screw adjusting and other carb fettling is a good idea anytime, because its easily changable when/if other parameters in the engine change for whatever reason. (free flow exhaust, or air cleaner, egr and or cat converter removal, etc.)

Very informative there.... Thanks thillskier....

[rjmorel]

FTEY,
Look at the caps to see if they have a adjusting screw in the top cap. Looking at your 2nd pic it doesn't look adjustable.
And the chain side of the rear hub, thats where the cushion hub would be so the chain and sprocket are cushioned from the rear hub to cushion the drive train from stresses. On non-cushioned rear hubs the sprocket is bolted directly to the hub. rj

[SpudRider]

Originally Posted by FTEY

....

Thank you for posting the additional photographs. If you have time, can you post one more photograph of the left side of the rear wheel, showing the rear sprocket?

[thillskier]

Unscrewing (unbolting)? the top of the carb slide assy,(where the throttle cable goes into the carb) and removing the slide with the throttle cable attached (still) whole thing should simply pull up and out. Then under the spring, there will be a clip holding the needle (spring is pishing down on a washer hiding the clip/needle assy.) Pull the clip off the needle, and RAISE the needle (go ONE ring position LOWER on the needle). This should richen the mixture and make it start run, and cruise much better for now. It may be too rich once its broken with a few more miles on it. It may be perfect if you open the air up a bit, also. You can still do as Spud suggested with the idle screws air adjustments,also. This just gives you a one step more fuel range to work with, which is usually needed on smogged carbed bikes.

If I had a manual, I could post up a carb (exploded view diagram) that would make this easy to see (and do). Its a 5 minute job, once the slide is out of the carb where you can access it and the needle.

Hope this helps. If your mmanual has a carb diagram, put the slide on a PM or here pic, and I can identify the parts and "walk through" it with you, OK.

[FTEY]

The bolts/nuts does not look adjustable. Will take another one from the rear left and post soon.

[FTEY]

Originally Posted by thillskier

Unscrewing (unbolting)? the top of the carb slide assy,(where the throttle cable goes into the carb) and removing the slide with the throttle cable attached (still) whole thing should simply pull up and out. Then under the spring, there will be a clip holding the needle (spring is pishing down on a washer hiding the clip/needle assy.) Pull the clip off the needle, and RAISE the needle (go ONE ring position LOWER on the needle). This should richen the mixture and make it start run, and cruise much better for now. It may be too rich once its broken with a few more miles on it. It may be perfect if you open the air up a bit, also. You can still do as Spud suggested with the idle screws air adjustments,also. This just gives you a one step more fuel range to work with, which is usually needed on smogged carbed bikes.

If I had a manual, I could post up a carb (exploded view diagram) that would make this easy to see (and do). Its a 5 minute job, once the slide is out of the carb where you can access it and the needle.

Hope this helps. If your mmanual has a carb diagram, put the slide on a PM or here pic, and I can identify the parts and "walk through" it with you, OK.

I will find if theres any pics of the carb. The manual seems like way too simple. Worst case i will just ride the bike to the assembly plant some 25miles from where i live and get them to rectify if its still this way.