WJ 200GY-B

Guy's, need info on the Wonjan 200 GY-B. I believe that it is Suzi DR 2oo Tech. Who knows what the spares compatabillaty are? I would also like to bring down the Rpm in top without dropping performance, Thought of swapping the rear sprocket from 56 to 48. Sugestions ?
I suspect that she is running a bit lean. On deceleration se barks and bangs quite a lot. You know, bangg.......bangg..bang.bang.bang.:lol8:

What info is to offer on this bike ? I have had only minor hassles, otherwise a pleasure. Pulls my 105Kg ass like a dream. I am currently doing an fuel economy test. Done 130km and not close to reserve yet. This already boils down to +- 15km/L.

Would appreceate every bit of info to offer.

Regards.

The thing with Chinese industry is that there are bloody hundreds of factories and it's difficult to keep track of them and their products...:icon10: everyday I find a new one I've never heard of before.
I've been looking at their web page as I thought only Qingqi produced DR200 engines under Suzuki licence.
The model listed under your model number doesn't appear to have a DR200 engine:

http://www.wonjan.com.cn/UploadFiles...2585143760.jpg

If this is not the one, can you give us a link to the SA importers site and photos?.

Our qingqi QM200GY-BA fitted with a DR200 engine, has the gearing at 15-48 and the general opinion is that the gearing can be raised to 16-48 or by swapping the rear sprocket at 15-44. This is about right for comfortable highway cruising without too many revs.

The popping on deceleration is usually caused by a weak idle mixture, normally the result of lean settings to satisfy emissions requirements, however, if it's a DR200 engine and is fitted with a Mikuni BST28 constant vacuum carburettor, it has a air cut-off valve or coasting enrichener that corrects this weak mixture by supplying extra fuel on deceleration only, to avoid banging in the exhaust. It's a sort of lump on the left side of the carb like this:

http://www.telecable.es/personales/a...eftsideACV.JPG

It may be inoperative and failing to do its job.

Another cause of banging in the exhaust is an air leak somewhere in the exhaust system. Could be in the pipe-cylinder head joint or a defective gasket there, or loose pipe nuts. Or it could be in the pipe-silencer joint.

I've just thought of another possibility. For some markets with strict emission laws, like the European Union, the exhaust contains an oxidation catalyser that requires extra air injected into the exhaust for it to work well. This extra air is pumped by a sort of reed valve device and it can cause banging in the exhaust. That's why I've removed mine. The photo shows the valve port blanked off:

http://www.telecable.es/personales/a...exhaustsai.jpg

Wolfie,

Welcome to the board! What the Forsc man says is correct. Probably runs lean for emissions reasons but he gives some good advice on what to look for.

Also, you can try to richen up your idle mixture with the Air/Fuel (A/F) adjustment screw on your carb. The engine on your bike looks honda based and you can probably adjust your carb by backing teh A/F micture screw out by 1/4 turns and see if that helps. Don't go too far out though, just enough so it lessens the decel-popping. Tuning a carb is a real mystyery of the universe and requires a bit of fiddling but I'm sure you can get it.

Swapping sprockets is USUALLY a painless job but you'll have to also shorten the chain a few links...esp. if you go from 56 to 48. If there are steps in between, you may want to try those as an 8 tooth drop in the back can be pretty severe and most of the time these bikes are sorted properly (more or less) from the factory so gradual adjustments over time are recommended. Does your bike use a 520 chain?

CC

Quote:

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Originally Posted by Wolfie

Guy's, need info on the Wonjan 200 GY-B. I believe that it is Suzi DR 2oo Tech. Who knows what the spares compatabillaty are? I would also like to bring down the Rpm in top without dropping performance, Thought of swapping the rear sprocket from 56 to 48. Sugestions ?

I suspect that she is running a bit lean. On deceleration se barks and bangs quite a lot. You know, bangg.......bangg..bang.bang.bang.:lol8:

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Quote:

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Originally Posted by CrazyCarl

Does your bike use a 520 chain?

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I don't know about Wolfie's, but my Qingqi has 134 links of 428 chain. It's a shame as it won't share sprockets with its sister, the Suzuki DR200. That uses 520 chain.
I'm told that the nearest sprockets that fit are for the Suzuki DR125. But Its front sprocket has to be machined to remove a wider centre boss.

http://www.telecable.es/personales/a...gqi/jtf409.jpg
For the rear sprocket, the one for the Suzuki TS125ER fits, but its only available normally in 44 tooth form. This, however is reckoned to be enough to raise the gearing for reasonable highway driving.

Not to hijack a thread, but the QingQi's in China (and probably the US...can anyone confirm?) use an o-ring 520 chain and sprockets.

CC

Quote:

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Originally Posted by CrazyCarl

Not to hijack a thread, but the QingQi's in China (and probably the US...can anyone confirm?) use an o-ring 520 chain and sprockets.

CC

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That's strange. I have a 2007 European EEC approved model and it definitely has a 428. It's even stamped on the sprocket along with the number of teeth.

Shees Guys, Thanks for exelent info. Maybe it would help if I yust mentioned that I am not completely unfirmiliar with the "doings and the screwings" of cars and bikes. I Have been restoring cars, esspecialy Volvo's from age 8 under Dad's supervision. Did some motor racing and offroad car racing.:naughty:

Forchetto:-

Jip, That is the one. Mine is Blue though. For a start I lifted my carb measuring needle by one slot. Thid made a HELL of a differance in the sound effects on De-cell. Still some there but not to much.


I am not sure weather it has a 428 or 520 chain. I have downloaded dimension tables on chains and will measure mine to determine the spec.

CrazyCarl:-
Sure dude, I am convinced that I will have to shorten the chain. That is no probleme. I dont think that it is possable to go 1 up on the front sprocket. The clearance seemes to be EXTREMELY tight. The gearing is extremely high,Carl. Before I reach the end of my street, 40 meters down I can be running 3rd gear. In top she does 8400 @ about 95kph. Lots of guice, but runs out of braeth. I have read a post of a chap that is runing the very same bike, in SA, on a 41 rear. I judt can not get hold of him to hear what his performance is like and what he weights. 48, according to my calc's, is a 14% change in FINAL DRIVE ratio. If you work this throug gearbox ratios and wheel dia.,its not that mean.


There are no strickt emmision laws in SA yet, but we have very shitty unleaded. 93 RON claimed ! I run just about everything with octane booster yust to make my motors sound a wee bit happier. I am thinking of blending methanol to improve the fuel propperties.

Tha for all the advise and tips.

Regards.