Modified Variator Noise on Take-off

[jruiz123]

I have a stock variator on 150cc Honda Vario which I had machined. It was re-angled/re degree to a certain degree. Other than that other CVT parts are stock. When I get on the gas from a stop or when I take off, it has this like a high rpm sound. And, when the scooter is moving, the sound is gone. Anyone knows why this happens to mu variator?

150cc Scooter specs:

15.5g x 6pcs rollers -  Stock

1000rpm Clutch Spring - Stock

1000rpm Contra Spring - Stock

[FrankenMech]

Slippage?

Did you get a belt to match the new angles?

[jruiz123]

Nov 8, 2020 23:25:07 GMT -5 FrankenMech said:

Slippage?

Did you get a belt to match the new angles?

No, I'm still using the stock belt which I have ran around 2000-3000km already. How to know if its belt slippage? and also the correct length?

[90GTVert]

If it's revving up on takeoff, it could be the clutch. It could be belt slip. If it was fine, you installed the variator, and now it suddenly revs, then I would guess it's related to the variator.

I'd start with figuring out if the spacing is right in the variator. If you've got more space between the vari and the fixed half, then it may slip because of that. Could be that the drive boss is too long for your setup. Also check belt width vs stock to be certain that you don't have excessive wear and a narrow belt. You may see black marks on the pulleys if the belt slips, you may not. The belt may show signs of high temp, like glazing on the sides.

Belt length is likely at least close if it's a stock belt. Ideally the belt should be able to sit at the outer edge of the rear pulley while it's riding on the drive boss up front. If it's way off with a lot of slack, then the belt is too long and if it can't at least be close to doing that the belt is too short.

You can usually get away with a mismatch of angles by at least a few degrees, but it may take extra break in time to allow the belt to conform to the pulleys. If there's a big mismatch between the front and rear pulley angles, then you will always have a mismatch and perhaps be more likely to get slip or noticed increased belt wear.

[jruiz123]

Nov 11, 2020 18:59:24 GMT -5 90GTVert said:

If it's revving up on takeoff, it could be the clutch. It could be belt slip. If it was fine, you installed the variator, and now it suddenly revs, then I would guess it's related to the variator.

I'd start with figuring out if the spacing is right in the variator. If you've got more space between the vari and the fixed half, then it may slip because of that. Could be that the drive boss is too long for your setup. Also check belt width vs stock to be certain that you don't have excessive wear and a narrow belt. You may see black marks on the pulleys if the belt slips, you may not. The belt may show signs of high temp, like glazing on the sides.

Belt length is likely at least close if it's a stock belt. Ideally the belt should be able to sit at the outer edge of the rear pulley while it's riding on the drive boss up front. If it's way off with a lot of slack, then the belt is too long and if it can't at least be close to doing that the belt is too short.

You can usually get away with a mismatch of angles by at least a few degrees, but it may take extra break in time to allow the belt to conform to the pulleys. If there's a big mismatch between the front and rear pulley angles, then you will always have a mismatch and perhaps be more likely to get slip or noticed increased belt wear.

I ended up returning to stock variator pulley and drive face angle, because of the noise. Im suspecting it was the boss was too long and the belt would just slip in lower rpm. When the variator was reangle I saw a significance in the space in between. didnt realize the gap was just to big of a difference with stock. Thank you all for your inputs. Its hard to find a stock/aftermarket drive boss in our location, and Im not willing to also custom my stock.