CVT Noise during take offs and with heavy load

[olivervillaflor]

Good Day Guys,

I am actually using a Yamaha Scooter here are some of its specifications

Make : Yamaha

Model : Mio Soul i125

Displacement : 125cc

Transmission : CVT

Stock Clutch Spring : 800 RPM

Stock Center Spring : 800 RPM

Stock Roller Weights : 12 Grams (6 pcs.)

Fuel System : Electronic Fuel Injection

Trouble Experienced:

It can only be experienced once I have a back rider, when i'm riding alone, i haven't experienced it.

During take-offs there is this vibrating noise along my CVT, but when i reach but after that during higher gears i don't experience it. It can also be hear once I am decelerating, and reaches a lower RPM.

I ve been reading threads before, but nobody has experienced this kind of trouble.

Actually the there was a thread where I read that he experienced an "Angry Sea Lion" Sound coming from his CVT, well to my experience I could also describe the noise I am hearing just like that.

[90GTVert]

I'd probably take the cover off and see if there were signs of the belt or clutch slipping. Thinking perhaps all is well with low load, but under high stress from added load the belt or clutch may start to slip.

[snaker]

1. Bad rollers
2. Bad driven pulley bearings
3. Bad clutch parts
4. Lack of maintenance of CVT - sticking, dirty

Have to dig in to know.

[olivervillaflor]

Thank you

For my scooter here are some of the things I’ve done as a troubleshooting process.

1. Replace Contra Springs (from 800rpm to 1000rpm)

2. Clutch spring are still (800rpm)

3. Replaced clutch bells, to eliminate the probability of it being warped

4. Replaced belt, this new belt has run for 166 miles only.

5. Cleaning of fuel system such as the injector and throttle body, idle speed is set to 1500rpm as the manufacturer standard.

6. I am using 9grams of 6pcs roller weights, the stock is 12grams. Since i an quite heavy and wanted to stay on low gear for a longer period, and most of the time i have someone riding with me.

7. Cleaned CVT system, roller weights, variator, clutch, clutch bell.

Initial analysis:

I am not satisfied with my take-offs, it seems like im on a high gear instantly. But before with the 9grams of roller weights installed, i am satisfied, but i overtime my acceleration got bad with my 9grams roller installed.

With the noise i experienced with heavy load, it can be related to a car full of passengers and from stop will be starting at 3rd gear, the car will either stall or judder, since there is not enough torque to carry the weight of the car and its passengers.

On a cvt system, gearing can be determined by the position of the belt relative to the front and rear pulley, and with respect to engine RPM.

I am always starting on a second gear, now if i have a back rider, the cvt reacts by belt slipping forcing itself to go on the first gear, this slip could be the noise that i hear. But not only during acceleration but also

When I decelerate, and goes on low gear.

What can be the possible causes of these:

1. Could it be the torque control grooves are worn, on my torque drive that the contra spring cannot retract back the belt on its highest point.

2. Is it possible that my variator face are already worn that it has left grooves to a point which it cannot go to the lowest point.

3. Is my clutch friction material too old that the materials are already swollen that it pre engages even before it should.
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