New Zongshen RX3 (ZS250GY-3) Dual Sport

[SpudRider]

Here are some tires I have mounted on the rear wheel of my Honda XR650L. The Pirelli MT21 is the second tire from the right.



From left to right, here is the list of tires in the photograph.

1) Mounted on the rear wheel is a K760, TrakMaster tire, size 110/100-18
2) Dunlop, D952, size 110/90-18
3) Pirelli, MT 21, size 120/80-18
4) Kenda, K760, TrakMaster, size 100/100-18

[FTEY]

Originally Posted by thillskier

You MAY not have any luck with re getting factory and or dealer support re the carb issue. This is because in USA (not sure about regulations and or laws there in Maylasia of course, they can be fined $20,000 a DAY from the time they adjusted it to an out of federally approved spec (again in USA, especially California, (as their laws are even MORE complicated than Federal EPA's) until it gets adjusted back to original spec/settings.

Thats why its hard to get the bikes running right in USA unless they are fuel injected or you install a jet kit yourself. (which will put the carb and bike out of approved specification, BUT will run like its supposed to, AND give max HP that the engine was designed to make. It also will make the bike run longer since its not on the ragged edge, temperature wise (due to it running lean, from not getting enough fuel). This is also what causes the issues you are trying to work through, ie. running crappy, stalling, bogging and not developing hp and tq when throttle is turned as more air goes into the engine but less fuel than it needs is added to the air.

Its really not hard to rectify this and I'm sure I can help you do it correctly if we can get a "exploded carb view" so I can number/label the parts I'm wanting you to adjust and change. You can then pass the knowledge and proceedures on to your fellow bikers there in your area. ALL the bikes that are sold in that specification will have the same issues, until the fuel adjustments are tweaked. Also, I should add, its not buying a pre fettled jet kit. Basically, you will be doing that, actually developing/engineering yur own (and others) jet kits. You MAY want to take some notes on what you do and settings, jets, screw settings, etc., as you can then write the info down, buy parts needed for the next bike, and ship them the parts already tested and fettled (by you) saving the purchaser a LOT of time and taking the carb apart and reassembling. Most kits sell for 69 to 99.00 here, depending on if it a multi cylinder bike, and or parts needed to get it running as designed (right.
You WILL be an expert at carb assembly, and dissassembly before you finished figuring the exact settings out, BUT its not difficult, just time consuming, and depending on how much of a perfectionist you are, how much time is taken, also! You will REALLy enjoy how much better the bike runs and starts, also the POWER increase. Critically, at low speeds, when negotiating rocks, logs off road obstacles, is when you get the most benefits from this. The ability to get INSTANT response, and GOOD power and TQ to loft the front wheel, slide the back tire around, jump an obstacle, etc. can make the difference in a crash (and injury!) to you and or the bike, ve no surprises, and ride on away!

I can get an exploded carb diagram if you can't find one probably...it may not be the exact carb you're using (ours are EFI here, so I'd be guessing on which carb and its hook up etc. on your bike), but similar enough to allow you to get the job done, anyways. Ideally you get an exploded view of the carb on your model of cycle, of course...

That would be a great way to understand the bike. But still not able to get the carb diagram. Since its still so new here. I can see and understand before go on to meddle with it. Not the most familiar person with engines yet. But a good place to start. Refuelled yesterday and still getting 8L to full. But consumption is not good at all. I managed only 85km on the he last fill. Could it be because the bike is still new.

[pete]

The RX3 is a nice looking bike....
But at 175kgs it's the same weight
as my XT660R with 1/4 of the HP..
Hope the 175kgs is with all the boxes etc...

[detours]

Originally Posted by pete

The RX3 is a nice looking bike....
But at 175kgs it's the same weight
as my XT660R with 1/4 of the HP..
Hope the 175kgs is with all the boxes etc...

Yes, 175 kg (385 lbs) includes the 3 panniers, racks, engine guards, skid plate and windshield. I don't know if it includes fuel, oil and coolant.

Full specs here.

[thillskier]

I suspect these engines are VERY "tight" when new, and will "break in" over a fairly large amount of miles (as far as mpg increases). My Cummins powered Dodge took 20,000! mies to get within 1/2 mpg of what it gets now. Took another 30,000 after that (till about 50,000 miles) to get to 20mpg hwy (at 65mph)! So it can take a long time to wear in all components in drivetrain. The gears, bearings, and all other moving parts all contribute some portion to friction losses, and will take much longer than the main rotating engine parts, but don't affect mpg as much as ring seal, and combustion related parts.

That mpg (or rather L per km seems low, BUT until it gets 1000 miles or more, just drive it and it will improve, probably by a large amount.
If its still not doing what it should after 1000-2000 miles or so, I'll find a exploded view for you (or maybe someone with a ZOng 200 and a manual, can link an exploded view of their carb, and I can walk you through it. The 200's carb should be very similar to yours, only a bit larger sized, so SHOULD look the same and rejetting/adjusting/fine tuning very similar.

I know Spud has rejetted his 200, as have others who posted it on other threads on chinariders, I'm sure.
You kn0w, THATS an idea also, find the mods thread for the 200, and read the jetting/carb adjustment section to see if you feel confident to do the job. PArts should be available from the same suppliers (taobao) Id guess. Hopefully someone can chime in here for you with that helpfull info.

You'd be surprised how big a difference the miles makes, and then just using what you have on the bike, but changing adjustments, will make re economy, drivability, and tq at or right off idle to mid rpm's 5-6000 or so) (most important re riding and mpg).

I am quite sure you can do it, when if you decide you MUST do it!
Believe me, this type thing WILL be calling you and talking to you when riding the bike, guaranteed. hehe I'm sure every other rider on here will agree with that statement thats worked on their bikes...

[thillskier]

Re not "meddling with it until you do your research, and get a comfort level with the task. Its hard to mess anything up permanently, but there are lots of very small items that need to be kept up with and replaced from whence they came also..

Many on here have successfully fettled their carbs, if not all. Its one of those tasks that can nearly always be improved some, however, and if you modify other things, will need to be done again after the other parts are installed (or removed, even in some cases hehe.

I suspect Spud has his 200 running very well by now

[FTEY]

Originally Posted by thillskier

Re not "meddling with it until you do your research, and get a comfort level with the task. Its hard to mess anything up permanently, but there are lots of very small items that need to be kept up with and replaced from whence they came also..

Many on here have successfully fettled their carbs, if not all. Its one of those tasks that can nearly always be improved some, however, and if you modify other things, will need to be done again after the other parts are installed (or removed, even in some cases hehe.

I isuspect Spud has his 200 running very well by now

Thanks. I suspect i will have the itch sooner or later. Talking to u guys here is already like attending classes. Great bunch of information im getting here. After yesterday and today's ride out, bike feels a little better. Cold start was not as difficult as before. It gets going in a couple of tries.

[FTEY]

Read Spud's mod on his 200 and some other modifications elsewhere. Sort of understand the basics of it. I think i need to find ot the jet size of my stck 1st. A couple of questions. Does a bigger sized jet makes it run leaner or richer? 2nd, i read about adjusting he clip up or down. What does that do?

[SpudRider]

Originally Posted by FTEY

Read Spud's mod on his 200 and some other modifications elsewhere. Sort of understand the basics of it. I think i need to find ot the jet size of my stck 1st. A couple of questions. Does a bigger sized jet makes it run leaner or richer? 2nd, i read about adjusting he clip up or down. What does that do?

Larger jets make the fuel/air mixture richer. The clip doesn't affect starting, it affects the mid-throttle fuel mixture.

Please start a new thread on this topic, here, in our Dual Sport Forum. You can give your thread a title such as 'Zongshen RX3 Carburetor Problem.' Starting a new thread on this topic will give your questions more exposure, and you will get more replies. I suggest you include some photographs of your carburetor in the first post of your new thread.

[CSCDude]

Originally Posted by thillskier

I suspect these engines are VERY "tight" when new, and will "break in" over a fairly large amount of miles (as far as mpg increases).

Our experience on the three US test bikes has been that they break in quickly. They feel new (obviously) on the first couple of rides, but they like to rev and they are very smooth. Our blue bike now has about 1200 miles on it and the yellow one has about half that, and they both feel great. My bike returned 71.43 mpg on the ride through Joshua Tree National Park a couple of weeks ago.



The Hanjin Germany has left Korea and is currently en route to Long Beach, California. The dockworkers are back at work. Things are looking good. As we learn more, we'll post it on the CSC blog.

[FTEY]

Originally Posted by CSCDude

Our experience on the three US test bikes has been that they break in quickly. They feel new (obviously) on the first couple of rides, but they like to rev and they are very smooth. Our blue bike now has about 1200 miles on it and the yellow one has about half that, and they both feel great. My bike returned 71.43 mpg on the ride through Joshua Tree National Park a couple of weeks ago.



The Hanjin Germany has left Korea and is currently en route to Long Beach, California. The dockworkers are back at work. Things are looking good. As we learn more, we'll post it on the CSC blog.

Hi Joe. When my bike blinked that its short on gas, I can only put in about 2.1gal of gas when the spec says it can hold abt 4.2gal (16l). Does your test bikes having the same experience.
thillskier says its made this way to protect the efi system. Did Your 71mpg record uses all the gas from the tank?

[FTEY]

Then again i hink i need to let he bike run for another few hundred km before i can really see mpg improving.

[thillskier]

Ride that thing! Thats the best you can do for it, and as you already noticed, its getting better, and I suspect rather quickly. MPG will go up as well, also rather quickly, I suspect.

[thillskier]

Thanks for the update!

[CSCDude]

Originally Posted by FTEY

Hi Joe. When my bike blinked that its short on gas, I can only put in about 2.1gal of gas when the spec says it can hold abt 4.2gal (16l). Does your test bikes having the same experience.
thillskier says its made this way to protect the efi system. Did Your 71mpg record uses all the gas from the tank?

The light starts blinking around 160-170 miles or so, and we usually put in something around 2 or 2.3 gallons when it was blinking (in other words, your bike is behaving like ours). I've had other injected bikes that behave the same way; the warning light comes on while there is still plenty of fuel in the tank.

On the RX3, the top fuel bar on the left side of the instrument cluster is twice as tall as the bars below it.



My experience is you can go close to 100 miles before that first bar goes out. The second bar (about in the middle of the gage) goes by pretty quickly, then it takes longer for the remaining bars to extinguish. When it gets to the last bar and then it goes out, you can go another 10 miles maybe before the orange fuel indicator starts flashing. We stopped for fuel when that happened on the Joshua Tree trip, because we knew there would be no stations for awhile and I didn't want to take a chance on running out of fuel. A big chunk of that ride was at freeway speed; I believe if we took it slower without a lot of stop and go traffic, the bike would do even better than the 71.43 mpg we recorded.

I haven't attempted to run the tank dry, nor do I think this is a good idea based on the fact that the fuel pump needs fuel in the tank to stay cool.