Jonway YY250T engine stalls By daviddahan (Read 2,762 times)

[daviddahan]

Hi guys,

Lately I am having an issue where after ridding the scoot sometime after a long ride (more than 10 miles) sometime just leaving the scoot running the engine will shutdown.

It is not reproducible easily which make me not trusting the scoot. it's like at any moment it can die on me.

I tried checking the fuel line from the pump to see if it gets fuel and it seems that it does even though when it dies I think that the hoses from the pump are dry.

After it stalls I can re-start the engine after many tries but it can drain the battery I am not very familiar with all the terms you guys are using but I was thinking to replace the fuel hoses and filter and maybe clean the gas tank (only if I new how??) since it feels like a fuel clog/blockage.

Can anyone give a list of hoses specs that I need for the replacement and maybe the fuel filter (non Chinese)?

Some pictures or instructions how to drain the gas tank (I could probably leave the hose from the gas tank to the filter open I guess)?

Regards 

David

[Guitarman]

First off, you need to check your valves. If you look in the library section here you will find videos on how to do that. It's not overly difficult. You may have a fuel blockage, but it sounds more like valves to me from your description.

[Alleyoop]

Yes, it appears the valves are not sealing and it is loosing compression. What happens is when the motor gets hot and the metals expand the valves are not sealing and it will not hold low rpms due to lack of compression. So you need to adjust the valves and to have a little gap so the rocker arm allows the valves to close all the way. Set the Exhaust Valve to .005-006 inchs and the Intake to .004 inchs. You will find that the Exhaust Valve most likely will not have any gap, that is because the Exhaust Valve gets a lot of heat with nothing to help it keep it somewhat cool. The Intake Valve gets nice cool fuel and air to help it keep cool.

Depending of which motor the scoot has the 244cc HELIX CLONE or the 257cc LINHAI CLONE here are two Videos on how to adjust either one:
Alleyoop

HERE IS THE LINHAI MOTOR:


HERE IS THE HELIX MOTOR:

[daviddahan]

I have the 244cc engine. is it that simple like in the second video?

This scooter was in the shop about a 2 month ago and were suppose to have it's values adjusted.

Since the day I took it to that shop I having too many engine related issues.

Regards,

David

[Alleyoop]

Yes it is very easy on the HELIX 244cc motor, I wish every motor was setup like that for adjusting the valves.
Take a picture of the Valve setting now before you loosen them I want to see if they messed it up and set them to tight in the first place(IF THEY ADJUSTED THEM).
Alleyoop

[daviddahan]

I will and will post them here.

Before I try it I think that I need to remove the plastics for that right?

Regards,

David

[Alleyoop]

Well that all depends if there is no access panel that you can take off and no means to get at them then yes.
Alleyoop

[daviddahan]

Hi,

I found the access panel but removed some extra plastics to take a good picture and here it is:

[daviddahan]

if you right click in the image icon and select to ope in a new tab you should be able to see the picture.

Regards,

David

[daviddahan]

sorry. how do I share a picture?

Regards,

David

[Alleyoop]

HERE IS HOW TO POST PICTURES USING THIS HOST. IT IS EASY AND FREE:

1. Click on this link:
tinypic.com/index.php

2. Click on Browse, that will link to your computer.
3. Find what you want to load.
3. Click on the name of the picture
4. Click on OPEN
5. Click on UPLOAD
6. Click on the LINK that starts with IMG.
7. RIGHT CLICK and CLICK on COPY
8. THEN Come here to your THREAD ON DOC.
9. RIGHT CLICK and CLICK ON PASTE.
Alleyoop

[daviddahan]

This is the picture.

Thanks.

Regards,

David

[Alleyoop]

WOW!! If they adjusted them like that WHAT A BUNCH OF MONKEY MECHAINCS.

The Left one is your INTAKE and the Right one is your exhaust. Both should be near the middle at you can see someone marked them with yellow. So loosen them up and they will flop loose then just slowly push them toward the center.
Alleyoop

[Guitarman]

CRIPES! That is SO far off man. You totally need to adjust them. I might even take that picture into the shop and raise a bit of stink about a refund for incompetent work.

[daviddahan]

I need to ask for a refund for more than just this. They weren't able to fix a simple issue with the bell. Thanks to alleyoop I sended the bell and shaked the wheel a bit and that solved that issue.

Only question I have is shell I follow the video instructions or just positron the valves the way told me?

Regards,

David.