Belts, Clutches and Springs...Oh My

[carlson]

Good Morning.
I have a 2011 Johnway YY250T and it runs great, but for one thing. When I start from a dead stop the scooter doe not start off smooth (it is like the bike is shuddering). I think the belt is slipping?
However if I hold the rear break and rev the motor (with the nice smell of burn rubber). The shuddering stops for awhile (a day or two), but doing this, I can only imagine that I am shortening the life of the belt.
Any suggestions on how to fix this?
Thank you for your time and information.

[scootinround68137]

I have been having the same problem with mine here. Have read alot of other people with the same problem and it was their cvt filters or a bad clutch or clutchbell... Mine seems to be skunked gas and a bad sparkplug.

Heres what I would do to check it out.

First:
Try putting your scoot up on its center stand so the rear tire is off the ground and put blocks under neith the frame or use a jack to make sure the scooter will not rock back and forth.. (you dont want the rear tire hitting the ground while you are reving up the rpms!!)

First check to see if the motor will rev up nicely and idle smooth. Then apply more throttle slowly, If it starts missing when applying throttle you either have bad gas, a bad spark plug or both. I would suggest draining the gas, refill and change spark plug with properly gaped plug.


If that is not the problem you will want to check your drive system. By doing the following.


Pull your cvt cover and check both the filters in the cvt cover and the cvt housing itself. Mine look like 2 pieces of of thin insulation. They should be easy to spot unless they are covered in dust(which mine were). Grab an air gun, leaf blower, canned air, whatever you have available and spray all the cvt cover and housing including clutch/clutch bell, variator, pully's and belt with air to remove all the dust. It is also safe to spray the bell and through the bell holes into the clutch with brake parts cleaner, just dont over do it and do not get it on your belt.

Start the motor and slowly throttle up. Watch the belt, clutch bell and front variator... see if any of the parts wobble.. You should be able to tell here if the clutch is slipping and causing the problem you are having because the tire will jerk instead of accelerating smoothly.

If nothing wobbles or makes noise try putting the cvt cover back on and test drive. If you are still getting the shudder at take off I would recommend a new clutch and bell. Might as well replace the roller weights while you are in there as well. LOL

Good luck! Hope this suggestion works for ya!!

[tylerjwilson]

I'm having the same issue with mine, however I don't seem to notice it unless I'm sitting on it with both wheels on the ground. I tried reving it up with the center stand up, and it seems normal. After reading various threads about taking apart the clutch and cleaning it out, and sanding the pads, I took a picture of mine. Any thoughts?

Attachments:

[carlson]

I looked everything over and it looks like I am going to replace the belt and the clutch and change the weights out.
But that leaves me to another question. Can you tell me if anyone makes a performance clutch for the yy250t and who should I go through for the parts?
I tried to see if MRP was still in business by sending them an email, but that was over a week ago and I have still not received a response
Thanks for the info.

[vader1701]

hello,

I am working on my CVT as we speak on my Yamaha Majesty and the symptom was that I had a vibration when I was going about 15 mph and then if I slowly accelerated it would shake a little more than I thought was normal. So, I dug into the CVT to inspect the following;

roller weights gummed up or flat spots worn in
glazing on the clutch pads

So I replaced the roller weights and also sanded the clutch pads with 400grit sandpaper.

Now I have made a video of this and many others doing maintenance so if anyone is interested please take a look at my YouTube channel:

LordDarthVader1701

[richardthescooter1]

When you are accelerating, If you go too slow the rollers weights will cause the shuddering until you reach a certain speed, if you want a smoother take off buy sliders.

[vader1701]

You know I was looking at those and not being real familiar with this stuff I stuck with the OEM known thing, I wrapped the CVT project up this morning and took the Majesty out for a ride and it seemed much better. Gonna keep an eye on this but I think next season after riding it for a while I am going to take it all apart and inspect the goings on in there and maybe then I will change it.

[chaz12]

When I first got my 250cc scooter, well I inquired on why it seemed to hesitate when first starting to go.. My reply was, it takes a second for the clutch to engage. So when giving throttle the engine will start to rev up, than the clutch engages and the scooter begins to move. My CVT clutch is still ok after 5500 miles, belt looks good still. But I regularly maintain it too. If I notice it not going as quick, or slipping, well that is when to change the clutch and belt.