YY250T vibrate badly By daviddahan (Read 2,551 times)

[daviddahan]

Hi Forum,

I got a YY250T, 2012 with about 800 miles on it.

I have an issue where when engine is hot (not over heated) and from a standing position will apply some throttle to move it it feels like the engine is almost chocking and vibrate really bad. if I play a bit with the throttle I can get over it and the it runs fine. 

I know it's not the valves. It is currently at the shop and they did the valves but it didn't solve the issue.

Any idea/suggestions?

Thanks, 

David

[Alleyoop]

If it shudders trying to move when you try to take off it probably are the CLUTCH pads slipping.
On the 250s it is very common they glaze up and cause it to slip when you go easy on the throttle starting off. All that is needed is take the Clutch Bell off and get a piece of sandpaper and sand lightly the glaze off the pads.

If the motor is actually BOGGING or sputtering when given throttle then the carbs Fuel Ratio Mixture needs to be adjusted.
Alleyoop

SO WHICH IS IT SHUDDERING and VIBRATING, BOGGING, SPUTTERING or HESITATING when given throttle

[daviddahan]

I passed the info to the guys that are servicing my scooter.

I will let you know what worked.

I think it's more SHUDDERING and VIBRATING.

[daviddahan]

Hi Forum,

It seems that the problem is solved.
The issue is related to your suspicion to "the carb's Fuel Ratio Mixture needs to be adjusted."

The air valve on the gas tank was broken. no air was coming in and after a long ride then trying to take off at that point too much air was getting into the carb and causing this behavior.

Thanks.

[Alleyoop]

Fantastic!! Ride save
Alleyoop

[daviddahan]

Spoke too soon.

I posted this when the mechanic called me and told me he solved the issue.
I went to pickup the scooter and drove from there to the inspection station and on the way back which pass close to the shop the engine stall and it seems that the problem not only wasn't solved but got worse. before the engine didn't stall. the vibration are still there.

I am worried that this mechanic don't really knows Chines scooters even though they are selling them.

This service already cost more than 500$ he replaced the carb and tried replacing many other parts with no success.

The scooter is back in the shop and I am waiting to hear form him.

Any advice you can give I will forward it to him. I am from MA and the riding season here is short I already lost more than one month because of this issue.

David

[Bashan]

Yeah I have some advice....go get your bike out of that shop and don't give them another cent. Get some pics, post them, and we'll figure this out. Rich

[serpic0]

Yeah I have some advice....go get your bike out of that shop and don't give them another cent. Get some pics, post them, and we'll figure this out. Rich



Boy I would agree to that.....
$500.00 and it still isn't running right?? GET YOUR SCOOT out of there ASAP!!!

[Alleyoop]

Yep, I ususally call just about all the scooter shop so called mechanics MONKEY MECHANICS they do not know how to diagnose a problem they are only good replacing parts and they hope one of the parts they replace fixes it and then hand you a big arse bill for parts and labor that were not needed. If you have some tools and a multi meter and just tell us what the scoot is doing in detail, LIKE when I give it a little throttle it dies or it bogs.
Does it start and idle or doesn't it start etc.. The more detail the better we can diagnose the problem.

It could also be the valves need to be adjusted and maybe is why it died on you after the motor got hot. So if you can follow some simple instructions with a few tools we can get your scoot rocking and rolling.

Alleyoop

[daviddahan]

I agree with you about replacing parts thing.
At this point I don't think I can pull out the scoot from them but I am not going top pay anything more.

The Valves were adjusted as part of this service. this is the main reason I brought it in.
I have another problem with those guys they are open only 3 days a week and if they don't finish the work on it within those 3 days I need to wait another week.

I will keep you posted as how it goes. I do have some mechanic skills but not familiar with some of the terms you mentioned like BOGS and other means but I looked it up in the dictionary and found out.

English is not my first language ;-).

Thanks,

David

[daviddahan]

Hi guys,

After a long time in the shop I fimally got my scooter back.

The bad news are that didn't fix the vibrating issue. I had a chance to take it to a different shop and the guy told me it is from the transmition after taking the bike for a ride.

Unfortunately this guys dont fix chinese scotters during the season only at the end of it.

I am riding it for now as is. I
The vibrations aee a bit morr controlable then before I put it at the shop. It might be that it was a combo of a bad carb and the transmission.

Is it possible that it is the rollers (not that I know what are they)?

Thanks,

David

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[Alleyoop]

Is it vibrating and shuddering ONLY WHEN YOU FIRST TAKE OFF?

BOGS is a sound it makes when you twist the throttle it makes sort of a BOGGGGG sound and it hesitates then it picks up and moves out.
Alleyoop

[daviddahan]

Yes. Only in the first few seconds. If I twist the throttle slowly it make the sound and vibrate but as bad as if I twist the throttle faster to take off in a reasnable speed.

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[daviddahan]

I maent to say not as bad......

David

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[Alleyoop]

I think it is your clutch pads they are all glazed and are slipping VERY common on the 250s due to trying to move the weight at low throttle. So take the bell off and sand off the glaze and it will fix the shuddering on take off. But so they do not glaze up to quickly give it some throttle when starting off then you can just back off but get the weight moving.
Alleyoop