Chinese Scooter Club

Ginger Phil

Big thanks to Billy Green for this step-by-step guide on how to derestrict a Baotian BT50QT9D. Cool

If you have a 125cc machine, dont bother, they aren't restricted!

Firstly I must remind you that while it’s not illegal to de-restrict a scooter/moped, it is illegal to ride one without the correct licence and insurance. Also this information is intended as a guide only, I am not responsible for any damage caused to your bike while using this guide. The responsibility for this lies with you!

Now on with the good bit!!

First you need to make sure you have the right tools, a medium size Philips (Cross head) screwdriver, a pair of pliers, and some electrical tape.

There are two parts to this de-restriction. First the CDI unit electronically restricts the engine. This restriction is easy to overcome. You need to disconnect the thin PINK wire under the body panel on the right side of the scooter (Photo)

The pink wire may be easier to find at the CDI unit in the battery compartment. There will be either 5 or 6 wires connected to the CDI.

If you only have 5 wires at the CDI plug, your scooter doesn't have the electronic restriction.
When you have disconnected this wire you will need to cover the ends with the electrical tape. DO NOT DISCONNECT ANY OTHER WIRE. The pink wire sends information about the speed of the back wheel to the CDI unit. If the CDI unit doesn’t receive this info (because we disconnected it!) it thinks you are not moving and will allow the engine to go to full throttle.

The second thing we need to do is a little more complicated, but still quite easy. We need to allow more petrol and air into the engine. Firstly petrol. Open the seat and you should see a cover in the bottom of the storage compartment.

Opening this cover by removing the silver screw will give you access to the Carburettor.

Remove the black circular cover (2 screws) VERY CARFULLY. There is a spring under this cap and it will pop out if you are not careful. When you have removed the cover you should see this...

Now carefully remove the rubber seal and the yellow disc will come with it. Inside this part there is a white plastic ‘Plug’ and a metal needle two small washers on it. One is loose and will fall off never to be seen again, if your not careful, and the other is fixed to the pin in a groove at the top. There should also be a small rubber washer, but this may still be in the bottom of the plastic tube. DON’T LOOSE THIS RUBBER WASHER.

Now you need to remove the fixed washer. You can do this by using the pliers to pop the washer off. Be sure not to bend the needle, it is easy done and would make it unusable! The washer now needs replacing onto the needle, but now, place it onto the middle groove. See photo...

Now you need to put everything back together. Replace the black rubber seal and tube into the carb first. When you do you will need to ensure that the small lug is lined up with the recess in the carb top, and that the seal is seated correctly.(See Photo)

Make sure the rubber washer is in the bottom! Now place the loose washer onto the needle under the fixed washer and place the needle into the hole at the bottom of the tube. Now place the white plastic plug into the tube, with the hole down.

On the under side of the black cap there may be a brass screw in the centre, if there is remove it. It looks either like this or like a long thin hexagonal nut.

Now place the big spring in and replace the cap.

That’s the fuel side of thing sorted. What you have done is to raise the needle a little, this allows more fuel into the carb.

Now we need to sort the air intake out. This is very easy, all you have to do is ensure that the intake hose is not kinked. This is a very common problem.
You can do this a couple of ways. You could place a plastic tube inside the hose to stop it collapsing or you could ‘zip tie’ the smaller tube to the frame, again stopping it from collapsing. I tied the small tube to the frame, see photo.

There may be a third step depending on the importer of your scooter. If you find that you are still not getting more than 35 mph then this may be you problem.

Importers have implemented this restriction in various ways. Currently and applicable to 50QT-7 scooters the restriction is implemented by the addition of a speed restriction ring in the drive pulley. This stops the 2 halves coming close together and increasing the final drive. Removal of this ring is quick and easy and will increase the top speed to around 45 to 50 MPH.

First you need to remove the drive belt cover. Once done you will see this:

You now need to remove the 17mm nut in the centre of the left hand (white) pulley. It is quite hard to remove, I recommend using an impact wrench. Then remove the front half of the pulley.
You will then be left with this...

Next just remove the slip ring from the drive shaft, they look like this, (there will be only one)

Once removed you should be left with the front drive pulley looking like this...

Put everything back together in the reverse order. Tighten the 17mm centre nut using the impact wrench set to 28 ft lbs torque.

You have now de-restricted your Baotian! Cool

A couple of things that would make the bike faster are

Changing the roller weights for lighter ones will increase the acceleration of the scooter. The roller weights that come with the scooter are 16 x 13mm 6.5 grams, I recommend using 4.5 gram rollers

You could also install a larger main jet in the carb. The standard size is around 78 or 80. I would recommend a size 90 and then fit a free flow air filter.

And changing the engine and gear oil for a good quality synthetic oil will make things run faster. Changing the oil should be done after the first 300 Km and then again after a further 300 Km. Doing these oil changes are cheap, but VERY essential.

If you need to, you can re-restrict the bike by putting everything back to how it was! However I would leave the air intake tube as it is.

Many thanks and Happy Scootering!! Twisted Evil

UPDATE!!

I have found out that a lot of the newer bikes, makes and models are all pretty much the same bike as the engine is the same, the derestrictions used before (pink wire, ring in drive pulley, and needle groove) have stopped being used. Instead they are using a smaller main jet in the carb, this restricts the flow of fuel into the engine and as a result slows the bike down. Some are also being shipped with a plastic spacer on the side of the carb, this stops the throttle lever from reaching 'fully open', again this slows the bike down.

I have done a guide on how to change the main jets, just follow this link.

http://taishanowners.proboards41.com/index.cgi?board=mechanical&action=display&thread=1136657880

Thanks again!
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Stanislavs1 · Posted: Fri Oct 13, 2006 8:54 pm Post subject:

How do you stop the 17mm nut from turning whenever you wanna take it off? Evil or Very Mad

adamsterdam · Posted: Mon Oct 16, 2006 10:44 pm Post subject:

Hi there has anyone ever de-restricted one of these BadBoys? Cool

I found a million and one electronic gizmos under the seat and fuel tank tonight, but what might well have been the engine management chip, might just as easily been the indicator relay! Confused

Is there a manual for this bike anywhere..? I bought it off ebay last month, its great fun but a bit sluggish up hills. Evil or Very Mad

Jialing · Joined: 09 Oct 2006 Posts: 3109 Karma: +90

Hi Amsterdam, Welcome,

My oh my you have opened up a can of worms with your bike. Icon_lol5

How would one describe it anyway, its not a scooter, nor a moped.
Its not a mini moto although it might be classed as a midi moto or maybe a maxi moto if they make one.

One thing I have noticed is that its chain driven, not belt like many of the scoots we have in the club.

The problem is how can we help you?

Now, because this is an entirely different animal to what we usually see here I think it would be best for you to start with the carb and follow the instructions in the desristriction guide for that.

Then I would check your cdi it could be under the seat or near your battery. count how many wires go to it and look for a pink wire.

Again follow the instructions in the guide. If there's no improvement you can always rejoin the wire should you decide to cut it.

Because it is chain driven I'm not sure if it has a clutch and gears or twist and go.

I would try to contact baotian if you can find them in china and see if they can supply you with manual in pdf format.

You might find someone in the UK who might be able to help you more.

Then again someone else within the club might come up with some other suggestions.
Most chinese bikes are similar. You will have to persevere and gain as much knowledge as you can about it.

Hope that helps... I also hope your carburetter is similar to the ones used on scoots. If so remove that brass screw under the black top plate of the carb and reset the needle.

Markindurham · Joined: 14 Oct 2006 Posts: 50 Karma: +4 Location: Durham

adamsterdam, I think that a good place to start identifying this beast would be to Google any info that you can find on the Maker's plate, assuming of course that you can find one Razz

Apologies if you've already done that Smile

Anyway, good luck. That looks like a real head-turner...

px166bajaj · Posted: Tue Oct 17, 2006 5:03 am Post subject:

You might find that a bigger carb (from a Honda C90) and a larger front sprocket (to raise the overall gearing) works. Its likely that there will be a big bore kit. Try googling "C50 performance parts" or similar. It looks as though a complete engine from a C90 would fit, but this seems a bit of a waste seeing your bike is new! Hope this helps.
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A dealer will say anything to get your money!

adamsterdam · Posted: Tue Oct 17, 2006 5:14 pm Post subject:

Thanks guys, what a warm welcome! Very Happy

The bike is a Baotian BT 49 PY 2A. It has a clutch and four gears (although 4th is only any use downhill). This is why tried to use the Baotian guide, as I'm guessing they probably haven't made too many different 49cc engines.

It's been bored to a whopping 72cc,. and the kid I bought it from said that there is a restricting chip in there somewhere, but I'm buggered if I can identify it!

I'm confident the carb will make a difference, but am also determined to find the restrictor and disable it! It's got about 150 miles on the clock now, and so I did an oil change last night too (and bolted the exhuast back on - it had vitually worked its way off!) and its running sweeter, but no faster! Evil or Very Mad

I've Googled the model no. and got nothing, and it doesn't feature on the Baotian site either! I'm wondering what's the best way to proceed! Does anyone know if its got a 'sister' model - I'm told that its a direct replica of a Honda bike!

Cheers guys,

Adamsterdam. Cool

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cb50j · Posted: Mon Oct 23, 2006 9:10 pm Post subject:

the real Baotian site

http://www.asia-motor.com/en/product_detail.asp?sID=68

found ya monkey

gazza · Posted: Tue Oct 24, 2006 7:42 am Post subject:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=9939&item=4609265731 it appears they are a pocket bike.whatever the hell that is

adamsterdam · Posted: Tue Oct 24, 2006 4:13 pm Post subject:

Nice one cheers guys Very Happy

I stripped her down at the weekend, until there was an engine and gearbox on a frame. Shocked

Everything was alarmingly loose so has been put back together with a bit more elbow-grease! I found the CDI, not sure it it was a restricted one, but have swapped it for one from a Honda-monkey-racing friend! Fitted a larger-bore inlet manifold too as the other one was quite narrow.

Going a bit faster now, but still dying up hills! Twisted Evil

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The Home of Beetle and Camper Hire

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px166bajaj · Posted: Tue Oct 24, 2006 5:30 pm Post subject:

What sort of speed do you get up hills. You don't have a lot of miles on this bike, be careful you dont wreck it!
_________________

A dealer will say anything to get your money!

adamsterdam · Posted: Tue Oct 24, 2006 7:54 pm Post subject:

Not sure exactly because speedo cable is currently broken, but I'd guess its about 20mph. It's 3rd for a gentle climb, 2nd gear for anything steeper!

I reckon I've done 100 miles on it since I've had it, and who knows how many miles matey before me had done - how long should running-in period be?

I borrowed a speedo cable from a mate, but the square-end didn't want to fit at the front wheel - if anyone knows of a different cable, and where I could get one, then please let me know!
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The Home of Beetle and Camper Hire

Taking Bookings Now!

px166bajaj · Posted: Tue Oct 24, 2006 8:02 pm Post subject:

Sorry thought it was a new bike. Those speeds dont sound too bad, you cant expect superbike performance from a little engine.

Re speedo cable, I expect its the same as a Honda C50 or a Monkey bike (ST50/70) you could do worse than try a Honda dealer, or look at his parts list, if he's helpful.
_________________

A dealer will say anything to get your money!

Beast · Posted: Tue Oct 24, 2006 8:17 pm Post subject:

does anyone know about de-restricting a taishan commuter?

jane · Posted: Wed Oct 25, 2006 6:52 am Post subject:

copied this from a post a while back, not sure if its sound, but gonna look at doing mine on friday. hope it helps.

Some info on de-restricting the Taishan Commuter scooter, this is for 2005 models with model number ts50qt-4.
The restriction is in the carburettor, remove the black cap held by 2 brass screws, you will see beneath the cap a plastic nipple and screw, remove the screw, also you will see a large thick rubber washer, this needs to be removed as well.
That is the only restriction placed on this model of scooter, there is no pink wire fix, no variator washer on the drive wheel etc, this info from Taishan UK!
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