Clutch Springs?

Hi all,

I have a 2000 Speedfight 2 50cc which I bought used. I have installed the:

Eco kit POLINI Peugeot Buxy/
Art.-Nr. P2415102

With the 7 gram rollers. At the time of installation I did not do the clutch spring (blue and white came with the kit) because I did not have a clutch holding tool.

The performance increase was nice - from 38mph to about 49 on the scoot speedo. I’ve just installed the:

Racing exhaust „Handmade ZX“
Art.-Nr. L4571

Again, without installing the little red springs that go inside the clutch because of lack of a tool. The perfomance „decrease“ was remarkable. Sloooooooow takeoff and sloooooow acceleration - roughly the same top end on a flat LONG road…but no torque to get it there going up any sort of incline.

I understand installing both the springs from the Exhaust as well as one of the springs of the Eco kit will rectify this and get my scoot about where I want it to be.

The 1st question: The eco kit came with a white and a blue tension spring. The installation guide indicates the white spring will increase it by 7%, the blue one by 15% → as I’m likely to have to pay to get these springs installed…I would like to do it just once, so I am looking for the best advice on which spring to use???

Last question… I do not understand what a „gear up“ kit is/does and whether I would really benefit from one on my setup?

I have no intention of messing with the carb (unless you folks think it’s required), neither do I intend to do a 70cc kit. What I was after when I started was just to increase the speed to around 50mph tops with a nice takeoff speed and good acceleration with sufficient torque to not suffer going up moderate hills.

All help/suggestions are appreciated! Thanks in advance.


Original von Albatros: Hi Ben,

This is gonna be a mouth full so bear with me…

Wow! What a wonderful reply!!! I’d have to say the most helpful and informative one I’ve ever received regarding a scooter question.
Thank you so much for taking the time to type that in!

I had not even considered the carb as I was paying too much attention to the springs that came with both the polini speed control variator and the LeoVince ZX exchaust. And I appreciate your offer of the use of your impact wrench as well – but alas, I’m 4,800 miles or so to your right. (From Georgia, living on Jersey Channel Islands UK right now - hence the „scoot“ instead of a motorcycle or car – much more practicle and easier to get a license for…and parking place!).

I would purchase an impact wrench, but as this scoot is the only thing I would need it for…and I will be leaving most things like that I purchase here when I return to the states — seems like a bit of a waste. I went ahead, yesterday, and put the scoot in the shop. I’ve asked them to put the white clutch spring in that came with the variator kit, the red shoe springs from the exhaust and asked them to rejet the carb. They asked „rejet it to what size“… lol

I told them what I was doing was not that unusual and I would hope they would know better than me…but to err on the side of caution and make it bigger rather than smaller than they think if they are unsure. They actually asked where I purchased the parts and will call them for advice (which sort of took me from unimpressed back to a bit impressed actually).

I told them I was going to be purchasing a less restrictive air filter so please bare that in mind… he indicated I should do that first before jetting it - which I understand, so I told him go ahead and jet it for the stock one…and if I’m not happy I’ll just have to have it redone.

I should get it back on Monday, I’ll post the results in this thread. Thanks again for the excellent reply and suggestions! Very very helpful.



Well… it comes from living on a 5x9 mile rock I guess. There should be a waiver that scooter riders have to sign on Jersey CI saying:

When you take your scooter in for any sort of work whatsoever, you understand you will be required to bend over and grab your ankles. No form of lubrication will be used.

The shop (which is one of the larger dealers on the island) installed the „shoe springs“ as requested (that came with the ZX exhaust) – the remaining THREE AND ONE HALF HOURS were spent trying to „true“ the clutch apparently. The torque spring that came with the polini speed control variator kit was NOT put in, as requested, because THEY said it wasn’t necessary according to the directions. THEY said the directions said to just put in the red shoe springs from the exhaust. Interesting those directions said that…since one set of instructions was for an exhaust with shoe springs and the other set was for a variator kit with torque springs. hmmmm…

Jetting the carb? Nahhhh… they haven’t jetted a scooter carb in years…don’t have the jets and didn’t see why it should be necessary. They were kind enough to only charge me the mere sum of 130 and some change for 2½ hours (he felt kinda’ bad about all the time spent trying to „true“ the clutch, since they couldn’t get it trued…) [:@]

OK…so here we are… What’s happening now…

The scooter is improved quite a bit…after it starts moving. When it gets up to 5mph or so it’s like a turbo kicks in and it flies at full throttle (or even modest throttle if I’m already moving…after a delay that is)…

Starting out…bit rough. Give it the juice and after 1-2-3 seconds depending on how much gas (full throttle is a good 1 second delay before movement begins)…movement starts off with a bit of vibration…like it’s slipping? Seems to be in 2nd gear as well at this point. Once it begins to move…it vibrates a bit more then starts to get up towards about 5mph I’d guess…then it drops down to 1st it feels like and takes off for a very rapid ride upwards to 50mph (+).

I’m thinking the following:

Purchasing an impact wrench, purchasing a „fly clutch“ (what else do I need with this? There’s a Malossi torque driver…would I need this as well?

Is there anything else I would need when replacing the clutch?

Next, forget jetting the carb I guess… replace it with? Which carb? and do I need to also purchase „reeds“, etc…what all do I need to purchase with the carb?

I don’t want to spend alot on this blasted thing…it’s a 2000 after all. But I’ve spent far far too much already (long story, cdi went…no master key, etc… screwed on tuneup just before that (327 pounds…!!!)… I want to get this thing running right and be done with it PERIOD.

Suggestions, advice, laughter?? All welcome…

thank you!


p.s., I will be doing all the work myself from now on…so any suggestions please include everything I need – I don’t need to get a clutch installed to find out I also needed to have purchased 27 nuts and a sheet metal screw or it won’t work. (sorry if I sound a bit „testy“…been a rough week! [:D]

Hi Ben,

This is gonna be a mouth full so bear with me. I’m from the U.S. so all the prices to follow are in U.S. dollars. If you live any where near Kenosha Wisconsin I’ll give you my cell and you could just bring your scooter by and I’ll help you take your clutch off in about two minutes.

If I understand you correctly, you have installed a high flow race exhaust and have not changed your carb and therefore you have probably not changed your air filter either. If you want the pipe to work correctly, you have to get more air into the engine. This will require a less restrictive air filter. Then you may have to rejet your carb or get a bigger one so that your fuel to air ratio is correct but this is not always the case. Some engines do just fine with the stock carb and jetting.

Once you have that changed; you will also see a marked increase in performance if you change your clutch springs to ones that are a little stiffer. This will increase the rpm’s of the motor before your clutch engages (before you take off). It is like taking off in a stick shift car. The more you rev up the engine before you let off the clutch, the more power the car will have.

As far as changing your final gears as with a gear up kit, don’t. This will make your current problem worse. A gear up kit is great when you have lots of power as with a 70cc kit or a high end 50cc that will be used on a track. For road use, stick with the stock gears. The gears are measured in a ratio of the drive shaft in relation to the idle shaft. So in a 9:1 for example as compared to a 12:1, the 9:1 would have more power on the take off with less top end. Conversely, the 12:1 will be harder to get going but will have an increased top end speed. The gear set you currently have will be fine once you fix the other problems.

I have a stock 50cc cylinder, a Technigas RS pipe and an Arreche 19mm carb with a high flow Unifilter. I am using the stock variator but I have put in blue polini clutch springs and the torque spring (that real big spring that goes in your clutch) that came with a performance pack that I purchased. It is probably close to the white spring you mentioned. It is longer than your stock torque spring. With this set up I get to 50mph with no problem.

The hardest part about working on a clutch is first removing it from the drive shaft. This requires removal of the clutch bell. Then the clutch just slides right off. The next hard part is taking the flange nut off of the actual clutch assembly. If you ever do this be carefull. The flange nut is under pressure from the torque spring. It probably wont hurt you if you just take it off, but it will spring apart , scare the s**t out of you and possibly damage your threads. To take both of the bolts off, I use a pneumatic impact tool. This is most likely how the shop will do it as well. If you live close to an auto garage, you might be able to get someone there to do it as well and probably for free. I used to use a universal holder that I made myself and a ratchet and socket but that sucked sooooo bad that I went to sears and bought an air compressor and air tools. If you look around you might be able to buy an electric one for about $100. Dewalt had one on sale at a local store today for $120. See what the shop is going to charge you to install the clutch springs. It might be worth it to buy an impact. Especially since you may not like your initial set up and may want to change it more than once to get it rite. Then you can change or clean your clutch components whenever you want. You may also need it to change the weights in your variator, if you decide to modify this part of your scooter as well.

To change the three springs inside of the clutch. Grasp the rear of the spring with a vice-grip plier and pull the spring back to strech it out and then up to remove it. The stock ones will come out pretty easy. The new ones will be quite a bit harder t