Variator spacer (washer) removal

[blaudp79]

Hi Everyone,

Has anyone tried to remove the spacer (washer) from behind the variator to allow it to push the belt further out and achieve higher higher speeds?

Thanks.

[agilebda]

I wouldn't attempt that. It's there for a reason! Critical to the alignment of the variator and back clutch. I presume something would get chewed up really fast ie the belt and crankshaft bearings would come under tremendous stress. Try different shaped sliders like the Dr Pulley or Tech Pulley Flying Roller to achieve the same you have mentioned.

[CROSSBOLT]

NOT ON A GTi300 or DT300i (same engine/CVT) !! Not if the washer you are referencing is the one on the crankshaft of the engine!! Real bad idea. First, it would widen the initial spacing of the front sheaves(pulley faces) raising the ratio, inceasing engine RPM for given road speed and REDUCING top speed.

[blaudp79]

agilebda: Different sliders would not help, because the once the ramp plate reaches the washer, it can't continue moving towards the crank shaft. Different roller shape can only change the acceleration profile, but has no effect on the pully ratio, therefore no effect on the top speed either.

CROSSBOLT: It is a GT 200i. The washer removal is commonly done on smaller scooter engines, to gain more speed. If you look at the variator cross section below, the spacer/washer sits next to the ramp plate (the crank shaft bearing and seal are on the other side) and by removing it, the ramp plate can move further out towards the crank shaft and the rollers can fly further out, therefor the V-belt can move further out on the pulley (because the two pulley halves are closer to each other).

https://www.pattakon.com/PatBox/CVT_range_expansion.gif
 

[blaudp79]

I did some research on this. You guys are right. Removing that washer would actually reduce the speed.
The washer that is commonly removed from small scooters is a different one, like the one below.

https://prohardver.hu/dl/upc/2017-04/363267_img_20170415_173500.thumb.jpg

[NorWeWa]

Check this to see if you your variator is being used to it's fullest.  Personally I feel the spacing between the moveable drive and the ramp should not be changed.  The spacer that is removed from the 50 cc machines fits between the variator drive plates.      

Art   

[CROSSBOLT]

I did some research on this. You guys are right. Removing that washer would actually reduce the speed.
The washer that is commonly removed from small scooters is a different one, like the one below.

https://prohardver.hu/dl/upc/2017-04/363267_img_20170415_173500.thumb.jpg

They did not get everything just right on these beauties but they got pretty close! The engine/ drive unit is about the best part!

[Ruffus]

@blaudp79, pls see below link to shed light on this subject.

https://www.kymcoforum.com/index.php?topic=30655.0

Though.there is a way, if a certain CVT by no means want to perform properly, even have to say KYMCOs engineers know what they do to produce affordable quality, which lasts.

Put the outer sheave of your CVT in a lathe and take off 1-1.5mm of material on its inner side (where the belt is supposed to run) by this measure sheaves have the opportunity to close further, and therefor pushing the belt until the outmost rim.

But takes a lot of measuring and roadtesting not to take too much off, otherwise your belt jumps out of its CVT and causes some headache.
Contra springs are playing a main role there too.

Was done at a LIKE 200i at the same 176ccm motor with good results.
Have to say that, I have a fully equipped workshop to my avail and several CVTs to fool around with.