Jonway YY250T engine stalls By daviddahan (Read 3,014 times)

[Alleyoop]

Well if that will not fit between the carb and the intake then make one out of a thin bar of metal like I said. You may have a piece of thin round metal or strong flat metal piece around that you can make one to fit in there and a nice long reach.

They even sell them for just that problem:

[daviddahan]

Hi Alleyoop,

I am going to take the plastics off again. try to do the fuel/air mixture adjustments following the instructions you posted a while back.

I took another ride yesterday with the scoot and it runs fine but it wasn't a long ride.

I am wondering if there is any chance that my issue is a combination of bad valve and air/fuel adjustment?

Do I need to re-adjust the valves after adjusting the air/fuel?

Regards,

David

[racerx125]

it is not necessary to adjust the valves after adjusting the f/a ratio as the valves are there just to help in intake and exhaust. The air fuel ratio is to adjust how much fuel and air enters the cylinder intake valves has the role of opening to bring the fuel/air in the cylinder and sealing to allow piston to compress properly same goes with the exhaust it opens to allow piston to push burned fuel fumes out and closing to provide a seal to allow piston to compress the fuel/air.

[gatekeeper]

Rule of thumb; make sure the valves are adjusted properly first then adjust the carburetor.

[kalee]

Aug 13, 2014 15:46:35 GMT -6 daviddahan said:

This is the picture.

Thanks.

Regards,

David

Alley, I think a monkey could have done a better job.
kalee

[Alleyoop]

Yep never seen such badly adjust valves especially when you can see the adjustment. I mean the center of the adjusters is normally where they would be set when new. The exhaust appears to be fully loose meaning it is not opening the exhaust valve all the way. The Intake one is also on the loose side also meaning the valve to suck in fuel and air is not being opened enough.
Alleyoop

[daviddahan]

Well as bad as it looks if I position the exhaust more to the left the engine won't start.

If I do that while the engine is running it lowers the rpm and feels like it is choking the engine.

Is their a possibility that something else is causing my original problem?

The engine sounds fine no banging or anything, run good as long as it runs.

I am wondering if it is possible that the carb was too much lean? is there such a thing?

regards,

David

[daviddahan]

Finally some good news.
Yesterday I put the original carburetor in and took the scooter for a ride and it seems like it is running very well so far. No stalling. I took it again today for a long ride and it perform as expected. It seems that the source of the problem was the carburetor that the mechanic put in was bad in some way.

Thanks for all the advise and help you provided me.

Regards,

David.