Jonway 50cc scooter turns over, but doesn't want to start. By kiewie (Read 4,126 times)

[Alleyoop]

Well that clicking sounds more like the valves and after seeing the adjustment stud it is no wonder it is clicking.

Did you put the rocker assembly on right the E X on the bottom? Also when you adjusted the valves did you bring it up to TOP DEAD CENTER? I can't imagine how that would happen when looking at that valve it appears to be up and closed and there is no GAP between the rocker and the valve stem.

Well now you need the adjustement screws:
Alleyoop

[Alleyoop]

Yes, change out the rocker with the stud and all. Also before you button it back up, align the cam with the two little holes even with the top of the head and the big hole up THEN ADJUST both valves to .003 inch's. And please take some pictures right after you adjust the valves I want to see to make sure everything looks good.
Alleyoop

[kiewie]

Yes to all!
And I know, weird thing though, when I adjusted it, it had the gap I could provide with a piece of soda can, and I could move 'em with the itty bitty gap I left. It was soda can thick though, for sure.... So, before I replace this.... Do I wanna figure out why it mutilated the screw... ?

[Alleyoop]

The only thing I can figure is it was not at Top Dead Center and it banged itself to death because if you look at it now the BOTTOM of the Rocker is on the Valve Stem. One other thing could be wrong is the Rocker assembly is not the right one and or you put it on backwards. Is the E X STAMP on the bottom?
Alleyoop

[kiewie]

E X Stamp is on the bottom. Made it top dead center just like the picture, and the video that you posted back on page one, when I replaced the assembly and adjusted the valve. Someone had mentioned something about the springs can go bad??? I just dun wanna have this happen to another part, cause I don't have any other back up ideas, and did really well to even be able to buy the assembly in the first place.

[Alleyoop]

Well it could be that rocker is for one of the other heads for the 139qmb motors. Some have a 69mm valve stem and some come with a 64mm valve stem. And because of that the Rockers are a little different. But you can take the OLD rockers that worked and put them on the shaft on this new rocker are assembly. The assembleies for both 64 and 69 are the same it is just the ROCKERS that are different because if the valves are 69mm the rockers have to have a wider opening from one end to the other.

So take the old rocker off and I bet it is different than the NEW ROCKER. Put up a picture of both next to each other, I will take the picture and save it for future use for other folks that may run into the same problem.
Alleyoop

[Alleyoop]

Here is a picture of what I mean just so you understand why the wrong ROCKERS would cause a problem and nothing you did caused it just the wrong part is all.
Alleyoop

[kiewie]

I will do that for you for sure!!!
But I have a question first.
Do I take picture of both full assemblies, Or just the functional bracket and both types of Rockers, or just both types of Rockers, I just want to be specific for you. :]

[kiewie]

Sept 26, 2014 19:26:07 GMT -6 Alleyoop said:

Here is a picture of what I mean just so you understand why the wrong ROCKERS would cause a problem and nothing you did caused it just the wrong part is all.
Alleyoop

Allyoop, you are so amazing! Thank you so very much for teaching me! I'll totally be donating to this site as soon as I have income!!!

[Alleyoop]

Thank you, I have hundreds of pictures that I label and use to help the folks out. Just the Rockers is good enough, if they are different you will also see the difference right away. I should have remembered same thing happened to another guy on SCOOTERPROFESSOR and I told him the same thing put the old rockers on the new assembly. His was because his scoot has a BN157QMJ motor and he broke his rocker assembley putting it on and the one he ordered was not for the taller head that comes with the BN157QMJ motor.
Alleyoop

[Alleyoop]

Here is how the guy on ScooterProfessor broke his rocker assembley then ordered one and it was the wrong one and just swapped the rockers from the broken one to the new one.
Alleyoop

[kiewie]

Pictures! Do you need different angles??

[kiewie]

I definitely see differences now, but it started confusing me for a moment, haha.

[Alleyoop]

Great, Yep the ones on the right are longer which are for the 69mm valves which apparently your head has and the new assembly you bought came with the smaller rockers for the 64mm head.
Alleyoop

[kiewie]

I'll be putting 'em in and letcha know how things go. :]