I can see from here that they are TT’s… either of them are great tyres so you got a good deal.
Never seen such a standard looking cygnus before, dont think its spent its whole life in that config but anyway its a good bike.
Now get a CVT and clutch kit for it and gain 2bhp for about $3000-$2000nt fitted.
Nice, it looks great. I say just keep it stock because it looks great,but if you want to start tuning a scooter then buy another one. 
Have fun and take good care of her. Oh and nice color choice, white is the way to go. That’s what my RSZ is too.
Transmission upgrade aint tuning, its free power with no drawbacks!.
[quote=“smellybumlove”]I can see from here that they are TT’s… either of them are great tyres so you got a good deal.
Never seen such a standard looking cygnus before, dont think its spent its whole life in that config but anyway its a good bike.
Now get a CVT and clutch kit for it and gain 2bhp for about $3000-$2000nt fitted.[/quote]
How?
You save 2bhp by eliminating the greater frictional losses in the OEM kit?
That’s the only way I can see it happening (obviously the engine output is unchanged) and frankly I find it a little hard to believe.
(Been wrong before though.)
[quote=“smellybumlove”]
Now get a CVT and clutch kit for it and gain 2bhp for about $3000-$2000nt fitted.[/quote]That sounds good but I have no idea what to look for or where to look for it. I don’t even know what CVT means and to my knowledge, this scooter doesn’t have a clutch. 
Judging from your website, you probably know exactly what parts I need. Is there something more specific you can post to help me find the parts? I’m in Kaohsiung. Here’s a better idea… How about I send you the money you need to buy the parts, and a bit more, and when you get the money, you can mail the parts to me at your convenience. 
That way I’d know I’m getting the right parts. 
I’m only half serious.
[quote]Oh and nice color choice, white is the way to go. That’s what my RSZ is too.[/quote]It looks nice but it will get dirty so fast! I’d prefer it grey or black. I bought a disk brake lock today, by the way. Better be safe than sorry. 
[quote=“Ducked”][quote=“smellybumlove”]
Now get a CVT and clutch kit for it and gain 2bhp for about $3000-$2000nt fitted.[/quote]
How?
You save 2bhp by eliminating the greater frictional losses in the OEM kit?
That’s the only way I can see it happening (obviously the engine output is unchanged) and frankly I find it a little hard to believe.
(Been wrong before though.)[/quote]
I’m also curious as to how a transmission modification creates more engine power… but this sounds like a topic for another thread.
[quote=“Ducked”][quote=“smellybumlove”]I can see from here that they are TT’s… either of them are great tyres so you got a good deal.
Never seen such a standard looking cygnus before, dont think its spent its whole life in that config but anyway its a good bike.
Now get a CVT and clutch kit for it and gain 2bhp for about $3000-$2000nt fitted.[/quote]
How?
You save 2bhp by eliminating the greater frictional losses in the OEM kit?
That’s the only way I can see it happening (obviously the engine output is unchanged) and frankly I find it a little hard to believe.
(Been wrong before though.)[/quote]
It just does…
I think its because the rollers weight is VERY heavy and the torque spring is too soft, it just slows it to a crawl.
This sexy man will show you what i mean :roflmao: :
http://www.youtube.com/watch?v=HwGKt4IVX6A
and after:
http://www.youtube.com/watch?v=4iIkq9alb2A
Ignore the exhaust, i proved that it added no power afterwards with dyno testing.
There is only one negative to this mod, fuel consumption increases by about 5-10%
No mate, transmission mods do not increase power. They change the effective gear ratio during acceleration allowing the engine to rev higher at any given speed below the top speed possible for the vehicle. That allows the effective torque at the rear wheel to be increased, which accelerates the scooter faster.
So, transmission mods make the scooter quicker, but it doesn’t make it more powerful.
[quote=“redwagon”][quote=“smellybumlove”]
It just does…
[/quote]
No mate, transmission mods do not increase power. They change the effective gear ratio during acceleration allowing the engine to rev higher at any given speed below the top speed possible for the vehicle. That allows the effective torque at the rear wheel to be increased, which accelerates the scooter faster.
So, transmission mods make the scooter quicker, but it doesn’t make it more powerful.[/quote]
Well all i know is it made 7WHP stock and 9.something WHP with the transmission.
Its a cvt so my head will explode if i try to understand it.
I guess perhaps its because the bike rev’s higher to produce more of its power.
You are both right and wrong. The transmission doesn’t produce power, it just transfers it. The transmission cannot add power between the engine and the rear wheel.
Power read off the rear wheel seems to be higher because the dyno operator doesn’t know what gear ratio to use to calculate power. A dyno measures torque and calculates power since HP = Torque x RPM ÷ 5252
You need to know the effective gear ratio at every step through the pull since any reduction gear decreases speed and increases torque, being a simple lever. If the gear ratio constantly changes, like in a vehicle with a CVT transmission, the only way to measure torque accurately is directly from the crankshaft or on a more sophisticated dyno that can take rpm data from the ignition system. Most dynos are fed a gear ratio during set up and calculate engine rpm from the speed of the rollers the wheels are running on. This works fine on a standard transmission but automatics will produce errors.
Your pulley and roller set up allows the engine to rev higher as the scooter accelerates at full load than with the stock parts. That is why you see more power on the dyno and faster times at the track.
1.2 seconds faster doesn’t seem like much and it’s hard to tell which run is faster just from the videos. On the second run, you gave a push with your feet off the get go. :no-no: That’s cheating. 
I think I’ll stick with what I have. My scoot is fast enough as is. I won’t use it very often anyways. I will use it mostly on the weekends and to run to the convenience store in the evening. It would be fun to have more power but I don’t need to spend more money on this scooter. It’s a utility for me, not a hobby. If the parts in question were to need replacing (I googled it, I know which parts they are now), then maybe I’d spend a bit more for the performance parts.
To put it simply the transmission upgrade gives the biggest power upgrade stage to stage than any other.
I didnt push off, it just seems that way as i was caught out by the quicker take off and to be honest that would of made like 0.00001 second of a difference!.
Its good that your happy with it, considering its age the engine is probably run in nicely and making good power compared to a new scooter.
In my experience the more miles put onto the Yamaha 4 valve engine the more power they make, so you probably have more than 7whp!.
It might even be modded as it is, you cant see inside the engine but there is a chance its running a 155 kit and probably already has a CVT upgrade come to think of it!.
Just need to get my BWS shipped up from Taichung, starting to miss riding now!.
I have had a few of my scooters modified in the past. Modifying the CVT by swapping the clutch spring, rollers and belt did change the drive (like changing the gearing)…but power seemed similar with each application.
lighter rollers = quick off the line acceleration at the expense of top speed. (go too extreme with these and you’ll be getting passed by the wave of scooters you just blew away off the line halfway to the next light)
Heavier rollers = slower off the line but much better top speed and drive in higher RPMs.
The manufacturers put rollers of a weight that is a compromise between both. From there, you should judge whether you need more ‘go’ off the line or more steam at pace (depending on what kind of roads you ride on the most).
The new BWS seems to have low ‘gearing’ and lighter rollers than on a Cygnus 125cc…this is probably to match it’s design to be a little SM-scooter. If I was to be doing anything to my BWS, I would be looking to make the overall ‘gearing’ taller with slightly heavier rollers.
Hi Everyone,
I just bought a scooter from a buddy who left Taiwan (Kymco Techno 150), and the belt snapped when I was driving it, so I decided to get the transmission tuned with lighter roller weights and a different variator which I think is also supposed to be lighter (I think it is the variator…it’s the thing that holds the roller weights inside of it). I am a little concerned that the rollers they used are too light though. When I drive now, the RPMs shoot up sky high right away, and it is a bit faster, but I feel like it has lost some of the “push” feeling that it used to have. Also when I am just cruising at a low speed around my small neighborhood street, the RPMs get way too high also. My tach only works up to 5k RPMs so I can’t tell exactly how high it is going, but it is definitely gets very high even when I am just giving it a little gas at a low speed. So here are my questions…
Does this sound like my weights are too light?
Could it screw up my engine to keep it this way?
How much would it cost to replace the roller weights?
Does anyone know a good shop for transmission modifications that I can go to in Taipei where the mechanic will know what he is doing and will make sure the weights are perfect before he sends me home? I live in DaAn so anywhere between here and NanGang is totally fine. I know of one guy who is great but he is in Jilong so I don’t really want to drive all the way out there.
Thanks so much everyone!
Best,
Tyler
Rollers are too light.
find out what weight they are now and what weight it was stock and i can help you out.
Also change your torque spring for a 1500rpm one (thats the spring holding the clutch on).
go to WRRP in Jung-he, they are very good with all manner of scooter tuning and more importantly are very honest and cheaply priced 
Thanks so much for the replies. Can you give me the address of that place in jung he? Also how much should I expect to pay for new weights? How much does that spring cost and if possible could you explain what that would do to change it? Thanks again. I will try to go back to find out about the weight of the stock and new rollers tonight.
Thanks,
Tyler
Yes, it is caused by light weights. Damned lightweights. the big spring is less important but smelly knows his stuff so listen to him.
They’re cheap, so buy new ones. with weights, grams make a big difference, and you DO want to get new round weights rather than old second hand un-round weights for smooth transition across the rev range.
get an accurate ±0.1 gram scale or better (heroin scales are great for this) from a science hobby store or mail order, if you do it yourself, and make sure the weights all match.
the 150 is a GY6 engine, stock in taiwan would probably be 13g… so i would put 11g in along with the torque spring i mentioned, shouldnt cost you more than $400nt installed by a shop, if they ask for more tell them to take a hike.
Tuning the transmission does net you more power but it will rev more and be quite annoying in town, if you want more speed just bolt in a big bore kit along with a cam, i think you can install a 61mm in the 150cc GY6, but its been a while since i worked on one so dont quote me.
Hi guys,
I checked with the shop and they said that stock was 15 grams and they put in 13 grams (I think he couldn’t remember if it was 13 or 13.5). I had my girlfriend explain my situation to the shop (seems to rev too high). The guy drove it and said something along the lines of “I understand his problem.” He said I can come back tomorrow and he will fix it up for free. He also said that I didn’t need to replace the spring, and I didn’t want to push it since he is taking care of me for free, so I will have to save the spring for a different day. The only bad thing is that he was talking to my gf and she was translating to me, and her scooter tech English isn’t very good of course, so I don’t actually know what he is planning to do tomorrow, except that he is gonna change something. He did mention that my scooter has an uncommon set up and he will have to order something to the shop tomorrow.
I hope I didn’t accidentally ask him to make it less powerful. It just feels like it is a little faster now but I don’t get the same “push” that I got with the old transmission set up, and it seems to be revving a lot without the acceleration to back it up, so I get the impression that something is not quite right in there. Also not sure if it matters or is unusual but the HP max is at 8000RPM and torque max is at 6500.
So you guys think I should go tomorrow and get the adjustment he was talking about? I guess it’s free so probably can’t go wrong right?
Smelly, just to be sure, it sounds like the way it is now I have less power than I should even though it is revving more right? That is what overly light weights do? I don’t think I want to go for the piston upgrade, so the tranny is probably the only thing I plan to do here and I am after the setup that will give me the best possible power increase.
Also, is my current set up a danger to my engine? I was supposed to drive up to WuLai tomorrow but wanna make sure the high revs won’t blow my engine.
Damn, 400 for the spring and rollers? I paid 1500 for just the variator and rollers so I guess I must have overpaid. Oh well…
Thanks so much for your replies. I REALLY appreciate it!!
Best,
Tyler