Drive belt turned in Dust - LOOK.

[Ronan Alves]

Hey Guy how are you?

you now that i restore a Aprilia SR50 and put a lot of add ons in this scoot. The last thing that i put was a polini corsa kit bought on enviromoto, and my scoot got a lot of speed and torque, the parts that i put was.

Polini Corsa 70cc kit
PHBG 19MM Carb
Koso Manifold
BGM Block Reeds
Polini Clutch
Malossi Variator
Boost Bottle
Leo Vince Zx Exhaust.

AND

a standar belt bought on scrappydogscooter.

I now with this parts i need to put a kevlar belt, but i don find a 757 17 28 kevlar belt, only 788 18 28, and i was afraid to buy this and not fit in my scoot, you now that i live in brazil, and every part take 1 month to arrive here.

I try to test my bike yestarday, runs pretty good, but after 30 minutes of run, the bike loose torque, seems like the belt comes os the pulley. Lucky i was if my wife in our car follow me and she takes me to my house to know what happened.
When i opened the case i found my belt in pieces. I know its a standar belt, but you think its supposed to broken like that? its 17 dollars belt, not a kevlar, but a scooter belt and i think its supposed to run a litte bit.

see the pictures and tell me something about... couse i continuos not understad what happened, i think its a garbage belt, a SCRAPPYDOGSCOOTER need to know that. The guy in this store are really great and thy need to know the quality of the products they sell.







bye.

[vvtr]

i have had the same happen to me, after installing a race clutch on my baotian qt9.
my new belt was gone after only 20 miles or so of hard riding.
i think you will find it is caused by high heat from too much friction.
something is causing it to slip.

did you grease the rollers / sliders? or do you have an oil leak from the seal behind the variator?
this could allow lube onto the variator faces and cuse the belt to slip.
i find it best to not use lube but keep the variator clean at regular intervals to keep it free of belt dust.

the problem on mine appeared to be the new clutch.
after i pushed it home (doh!) i stripped the variator cover off to find the clutch bell blued with heat.
on closer inspection, the friction pads of the new clutch were only touching the drum in the corners & so allowing it to slip.
on the road this felt like very slow acceleration with quite a bit of vibration, but as i did so many mods at the same time it needed a good run....

i ended up removing the race clutch and refitting the original one but with the contrast & small springs from the new one.
back on the road with another new belt, the problem was gone and the belt has been on since with very little wear.

so, i would suggest with your scoot, before fitting a new belt again, you need to check there is no grease or oil on the variator, check the rollers & sliders, and the plate can move freely and also take a look under the clutch bell to see if there is any heat damage.

if there is slipping / glazing on the clutch friction pads, you may be able to clean it up with coarse emery paper.

i would also suggest that you run the engine on the stand and pop the variator cover off with the engine running and rev it to see what's going on with the cvt.
there are a few good videos of cvt working on youtube - particularly this one:


remember the engine will not start with the cover removed! you can bolt it up with just a few bolts then remove it when the engine is idling (carefully - dont go poking fingers near the moving bits lol)

i think you will find it's the friction pads on the polini clutch that are not fully making contact with the drum & causing it to get too hot.

[Ronan Alves]

ok man.. thanks a lot!!

i will see what happened with the system an disassembly everything to have an idea.

If i see something different i post here, but last time i run with the cover off and see it was everything ok.

the variator its oa and the clutch too, you think its was a bad belt? a kevlar belt it will be the same?

[90GTVert]

I found out a while back that I cannot use those cheap belts on anything I own. I ordered a few cheap belts from scrappy for the 2Ts and the 4T I had at the time and they all broke belts fast. They may not be bad on a stocker, but on modified stuff I was breaking belts in just a few miles at times. I switched back to Bando belts, not even the kevlar Bando, and the problem stopped. You should definitely check over your transmission, but get a kevlar or Bando if possible.

[jmkjr72]

yeah you dont need kevlar
on the zumas all of us run oem yamaha belts unless we are running an over range

i would check all my trans part and put in a brand new oem belt
i would never touch anything made by dayco if i could help it (i used to work for them)

[Ronan Alves]

ok man i will be very thank full.

look my original belt to my aprilia sr minarelli is 757x17x28, it will fit a stage 6 oversize variator kit with a 788x17x28 bandoo belt?

i think a need a long belt with this overrange vario right?

[jmkjr72]

yes if you do an overrange you need a longer belt
the stage 6 overrange should run the malossi overrange belt