variator Naraku 5.5g - Kymco 4T

[Bray0671]

Will I have this  problem

[mono]

My 2 cents :

Forget about variators, whether it's a racing type with an increased range or just a cheap no-brand imitation of the original, there's always something you loose compared to the stock one...

The stock Kymco variator is OK in a lot of ways. After some experiments with other variators I settled for the stock Kymco variator, which proved to be the most reliable and wear resistant, and it doesn't eat belts...

The best thing you can do for your CVT is to get a torquedrive with straight guide tracks instead of the standard curved guide tracks, and adjust the roller weights for the right rpm for your setup..
This kind of torquedrive (Malossi or NCY for example) will keep the engine within its powerband all the way from takeoff to top speed, which no variator can achieve with the standard torquedrive...

[skippy]

My 2 cents :



The best thing you can do for your CVT is to get a torquedrive with straight guide tracks instead of the standard curved guide tracks, and adjust the roller weights for the right rpm for your setup..
This kind of torquedrive (Malossi or NCY for example) will keep the engine within its powerband all the way from takeoff to top speed, which no variator can achieve with the standard torquedrive...

sorry mono. you lost me there. what do you mean?

[mono]

The torquedrive has guide tracks for the guide pins that are attached to the shaft of the fixed driveface.

Because of these guides, when the torquedrive moves sideways to open or close the rear pulley, it also has to turn relative to the fixed driveface. The drive belt is clamped tight between these two parts, so it will take a certain number of rotations for the pulley to open or close because the belt will have to slip between those surfaces (in a dynamic way, not really slipping)..

This means that the upshifting of the CVT on acceleration is delayed by a certain amount, and it also means that the torque of the engine has some influence on the balance between roller weights and contra spring, increasing the rpm a little when you open the throttle...

Because of these effects, the shape of the guide tracks in the torquedrive has a lot more influence on the way the CVT works than the shape of the ramps in the variator ever will...


If you're looking for maximum performance, the CVT should keep the engine at the rpm where it delivers its maximum power during acceleration, and the standard Kymco Agility torquedrive with its curved guide tracks just won't do that, no matter what type of variator you have !!

Funny thing is that all Kymco scoots that are actually made in Taiwan already have straight guide tracks in their torquedrives... It's just the Agility and other cheap Kymco types that are made in China which have the curved guide tracks - and also most chinese 139QMB scoots and cheap replacement parts have this configuration, which I regard as a fault instead of a feature  

Get a torquedrive from Malossi or NCY instead of one of those crap variators and you'll be happy  

[Bray0671]

Yea I have seen all the talk on that subject I still think a race varaitor will also help along with a straight torque driver. I still didn't get a answer if the starter will rub like in the post earlier on my belt from derestricting the scoot

[skippy]

depends. no one on hear has realy mentioned it. but every garage / shop told me to do this... i had trouble getting a good belt for the scoot. i have 3 belts (new) in shed.

1 was a gates belt sold for the agility. but the belt is to short,by 1" or so leading to slow acceleration as its like its in a high gear.also lower top end as it cant travle far up the varaitor. very well made belt though.

2 unbranded belt again to short

3 was a narkau hq belt. again sold for the agility but was too long about 1/2" longer than std that hit on the starter bendix. on top of the belt you could see 3mm ware on the belt from the edge in.and about 1mm deep after 2 weeks(could also hear a funny noice at speed) the belt was hitting the starter bendix.

i asked around in some shops and they told me when derestricting an agility 50 the bendix has to be taken out.

i am now using the narkau belt. and i have not had a problem since.fantastic little belt.

most people on hear rave about the bando std belt. which is fantastic. perfect length well made and norm lasts 13000kph. a clear choice winner but cant get one in the uk..... so with the std belt it may be ok with bendix in....but other brand belts if a tad longer take bendix out...

i guess im saying is.. try it first when you de restrict the scoot keep an eye on the cvt every now and then.its all trile and erra.

the best tip is keep it all clean as a clean cvt is the best mod. dirt and grime/ dust will only slow you down. if its all clean you will get the best out of her.

[mono]

Yea I have seen all the talk on that subject I still think a race varaitor will also help along with a straight torque driver. I still didn't get a answer if the starter will rub like in the post earlier on my belt from derestricting the scoot

OK, I'll give you the simple version then :

Yes, even with a better torquedrive, a race variator will give more top speed than the standard one - but it does so at the expense of more wear of both belt and variator - and you could achieve the same top speed by just shortening the boss of the standard variator without the extra wear....

The bendix rubbing the belt is simply caused by the belt being pushed too far towards the outside of the variator, so the faster your setup can go, the higher the risk of this happening - this will be different for all variators out there, so we can't tell, you'll just have to try for yourself...

For better acceleration a race variator alone will do almost nothing - people who say that it did make a difference for them have just delayed maintenance on their old variator for too long before they tried the new one... You'll need a decent torquedrive if you want to have a decent CVT behaviour, simple as that...

[mono]

i asked around in some shops and they told me when derestricting an agility 50 the bendix has to be taken out.

I think I'm not the only one to have done 80km/h (50mph) with the bendix still in place and no damage done - do these guys really know what they're talking about ? 

[Bray0671]

So what changes have you made to your scoot to make go 50. I have only put a smooth boss and 52 jet I am now giong 38 to 43 on the flat and down hill. Ate you saying that if I ad a new torque driver and different weights with every thing else stock I will go 50?

[streido]

I think I'm not the only one to have done 80km/h (50mph) with the bendix still in place and no damage done - do these guys really know what they're talking about ? 

Bendix worked fine on mine using a stock belt, didnt rub at all even hitting upto 52mph-53mph.

[skippy]

So what changes have you made to your scoot to make go 50. I have only put a smooth boss and 52 jet I am now giong 38 to 43 on the flat and down hill. Ate you saying that if I ad a new torque driver and different weights with every thing else stock I will go 50?

you mean 82 jet.....

with the bendix its trile and erra. see if if it rubs or not... is i said i have a longer belt in mine and it does rub.so bendix out. looks if you have the sdt belt then its ok leaving it in.

[mono]

You'll need either a BBK or a downhill stretch of road if you want to achieve 80kmh/50mph, because a standard derestricted 50cc will never generate enough power to do this on its own...

Shortening the boss of the standard variator alone can bring you close to 80kmh/50mph if belt and rollers are fresh, and your engine has enough power or "downhill support" - also an oversized rear tyre will help - while cutting the CDI to remove the rev limiter will do the rest...

A torquedrive with straight guide tracks doesn't do much for top speed, but it will give better acceleration all the way from takeoff to top speed because you can install lighter rollers, since it won't over-rev like the standard torquedrive does at lower speeds...