Shanghai Shenke YY 150-12 scooter Ignition Problems Help!

[SeeEmComing]

To the forum,I have a Chinese 150cc four stroke air cooled twist and go scooter with an ignition problem. After I installed a new cylinder head,the bike ran for about 100 miles then began to missfire and quit running shortly there after . I stored it for two years after that ,when I checked for spark then,it had one! So I charged the battery and put in fresh gas; and believe it or not the scooter started up and ran briefly. It did this a few times and then would no longer start. Apon checking for spark again , it once again DID'NT have any.Can anyone help me diagnose this problem or suggest what may be wrong with my scooter.

P.S. Does anyone have the electrical values for the components of this bike's ignition system? Or can anyone help me obtain a official factory repair manual or web link to same or web page that would have this information. Much thanks for any assistance you can give me with this problem. SeeEmComing

[oilyhans]

generally there are no 'official' service manuals for most chinese scooters
you can search for a generic gy6 service manual ....
the misfiring(back firing) is usually caused by the exhaust valve
lash (gap) too big
this can also make for hard starting

oilyhans

[SeeEmComing]

Hi Oilyhans,
thanks so much for the information but can you tell me besides the
misfiring which is as I said was a problem having to do with the valves
and a replaced head which I should have stated is a problem that I
think that I've licked Can you give me more information on in
particular the ignition system itself do you think there is a fault in the
wiring or do you think it is a problem with the HT coil, faulty igniton
switch, faulty ignition source coil, pulse generator coil, or faulty ICU.
In this generic manual Haynes Service and Repair Manual for Chinese,
Tiawanese and Korean Scooters (twist and go) They state that it is
more likely a problem with the wiring, than a component, of the above
listed components. Do you think this is the case? or it is a simple wire
harness problem? Where should I go next with this ignition problem?
the scooter is a Shanghai Shenke Superscooter 4 stroke 150 model
YY 150 - 12 Limited Edition 2 valve single cylinder it has a 48 on the
left front fairing Superscooter on the front wheel fender The frame
# is L8YTCKPZ78012200 Also if anyone on this scooter forum has
this scooter and has run into similar problems i would greatly
appreciate, any and all help that they could give me on this problem,
as I am stumped and I realize that I don't want to have to buy all these
components as my funds are very limited. I do know that alot of times
the same bike models have the same or almost the same exact
problems. thanks again oilyhans and all responding memebers
of this forum

Thanks Again,
SeeEmComing

[LongHairedCountryBoy]

It'd be nice to know if these things have a "rev-limiter"(?). Typically it's a solid-state unit, and lots of times are part of the Electronic Ignition Control (actual name?) module. The ECI unit could be intermediately breaking-down, thus losing spark.

Some simple things to check would be of course the spark plug (I've pulled bad brand-new plugs out of the box :^( ... the spark-plug boot, the coil wire at both ends (coil and plug boot ends). Also check ground connections, as a bad ground connection can cause all sorts of issues, including (but certainly not limited to) the issue you describe. Check of course all plug-in connections. NEVER jump-start one from a car, as this will surely fry the magneto. You don't won't to charge the battery with it still connected to the bike's electrical system ... disconnect battery before charging.


Good luck!
I hope this helps ;^)

Keep us posted!

[SeeEmComing]

Hi longhairedcountryboy,

I greatly appreciate your input and ideas in helping me troubleshoot
this ignition problem, I do not know if these scooters have a rev
limiter. I have replaced the original spark plug with a good quality
American made spark plug, of the same specs. The original was
a chinese brand under the brand name "torch" I will try all of the
things that you mentioned, you gave me alot of good ideas, when
I replaced the plug the scooter fired for about one minute but than
began to sputter and then die. The new plug when removed was
wet with gas, not that this is the problem necessarily. the scooter
has an automatic choke and I checked this and this seems to be
functioning The generic scooter manual I have
HAYNES says that none of the components in the ignition system
are not adjustable in value, that they are fixed value coils, and that
nothing is adjustable, It seems as if these scooters rely on replac
able electronic components alot- electronics -not electro-
mechanicals (that have some capacity to be adjusted in value.)
I will check all the grounds for the harness and components,
In my experience -with other chinese electronics -I have seen
alot of sloppy rush rush soldering, and seen bad solder joints,
where the solder was not correctly fluxed and the the joint broke
away just by tapping it. I emailed an American part distributor
for the exact HT coil for this exact bike asking for the exact
ohm value
across this coil, and he replied he didn't think you could tell if
a coil was bad by using this value AAARRRGGGHHHHHH!!!!!!!
obviously a manager, not a technician. The most frustrating
thing about these bikes are that they come with a rinky dink
hand drawn manual with no schematics or values or photos-
the manual that came with this bike was totally useless!!!
Apparently the Chinese don't write mech manuals for these
bikes. I emailed the original manufacterer in China like
four times and no response. I will get this bike running and
keep you up to date on what I find as to the problem with
the ignition and post it here for the benefit of all others in this
forum. Much Thanks For Your Response

Thanks Again,

SeeEmComing

[John]

Try the forum skootdawg.com All things Chinese! Ask and someone may have a ignition answer for you.

[oilyhans]

[SeeEmComing]

[tortoise]