China CRF50 frame, and 125 Ducar motor

[DANNYGEALE]

hi guys

im new here my son just bought a 50cc pit bike with a 125cc motor
when he bought it he was told the carby needed a clean out and it would probably be sweet

But i havent been able too get it going ive taken the carby apart and cleaned it perfect all the jets mad sure the seals were good put it back on and it jus wont start\

i tryed too kick it over nothing it wont start
i order a new coil it came today i put it on and nothing it wont start lolz


hes a picture of it


hes a picture of the carby


SO my question is the carby is obvious flogged out would i be able too get a replacement or too get a better one that would jus bolt on

how should i go about it

 

[Blender]

it may not be the carb is the engine getting spark? take your spark plug out, attach it to the lead and place it on the head (to earth it) and kick it over. you should see a faint blue spark. the brighter the better your spark is. also, did you check for any air leaks ? spray some wd40 or inox around where the inlet manifold attaches to the carb and head, and see if any is sucked through.
Welcome to MiniRiders by the way

 

[DANNYGEALE]

no worries mate ill give it ago tomorrow

ive tried to see if i have spark but i cant see anything

ive replaced the spark plug and the coil but i still dont have spark could this been a magneto problem ?

 

[my67xr]

welcome to Miniriders,

your sons' pit bike is a CRF50 based bike, the PW50 are Yamaha style

i can see that the spacer/insulator is missing from inbetween the carby and manifold

it looks like this one-
http://www.ebay.com.au/itm/Pit-bike..._Parts_Accessories&hash=item4abc2bb4c2&_uhb=1

without it fitted there's a good chance that it is sucking air in between the manifold and carby.


dont forget to drop by to the Introduce Yourself thread and say g'day too

 

[my67xr]

there should be a rubber boot on the top of the carby on the end of the throttle cable,
otherwise it will be sucking in air through there too.
and the throttle cable needs to be tightened up a bit too, to take the slack out of the cable
a couple of mm's play is ok.


and check that the coil has a good/clean earth point too, bare metal it where it mounts to the frame

 

[DANNYGEALE]

Thanks for that info on the frame mate

 

[DANNYGEALE]

and check that the coil has a good/clean earth point too, bare metal it where it mounts to the frame

So jus wire brush the frame so its bare metal ?

 

[Blender]

also, i think i just found your problem. the is supposed to be a plastic washer between the carb and inlet manifold. in your second picture, its not there. your carb also looks like a china copy of the mikuni 26mm?

 

[DANNYGEALE]

i think this Carb has a few problems the throttle cylinder in the carby seems too get stuck and doesnt move up and down too good i wish i could explain things better

 

[my67xr]

also, i think i just found your problem. the is supposed to be a plastic washer between the carb and inlet manifold. in your second picture, its not there. your carb also looks like a china copy of the mikuni 26mm?

lol, see post 4 Blender



with the carby,
for the 125cc engine, i'd recommend something like this,
http://www.ebay.com.au/itm/PZ-19mm-..._Parts_Accessories&hash=item3a85e1e20c&_uhb=1
they are easy to adjust, and are suited to a 110/125 engine


this is the same Keihin copy carby you have now, they are pretty easy to adjust
http://www.ebay.com.au/itm/26mm-Car..._Parts_Accessories&hash=item3a7bb1e840&_uhb=1


a slightly better carby is the china copy Mikuni 22/26
but they are a bit harder to adjust, as the mixture screw is underneath
http://www.ebay.com.au/itm/26mm-MIK..._Parts_Accessories&hash=item3cd6b62fdc&_uhb=1

 

[my67xr]

So jus wire brush the frame so its bare metal ?

yeah, or use some 80 grit sandpaper or similar, then smear some grease over it to stop it rusting later

 

[Blender]

lol, see post 4 Blender

lol, yeah, just noticed that, i typed it at one time then posted it at another , lol

 

[DANNYGEALE]

what do you guys think about the no spark as well ? ive changed the spark plug and coil could the magneto be buggered as well can ya test it with a multi meter

 

[Stubsy]

Heck ya killswitch mate. That will cause no spark too

 

[DANNYGEALE]

lolz yeah ive checked that mate no spark either way

 

[my67xr]

pull the spark plug out,
try holding the thread of the spark plug, and rest you hand on the engines head, then kick it over
see if you can feel a tickle from it

 

[DANNYGEALE]

pull the spark plug out,
try holding the thread of the spark plug, and rest you hand on the engines head, then kick it over
see if you can feel a tickle from it

Gday mate i tried what you said and ive got zero spark


ive already changed the coils and Spark plug... do you think the magneto is flogged out

 

[my67xr]

you will need a Multimeter to test the Stator.

find the wiring that comes from the Stator, on the l/h side of the engine, it exits the cover just above the front sprocket.
follow the wires up, and you will find where they plug into the bikes' loom.
disconnect the plugs/sockets, checking that the wires are plugged into a matching colour socket.
if they aren't matching, write down what plugs into what, for reference when plugging them back in again.




set your Multimeter to 200 ohms,
the reading on your meter should show 1, this means there is no circuit.

now, put one lead from the meter to the green wire coming from the Stator
put the other lead to the blue w/white stripe coming from Stator,
your meter should read close to 130 Ohms

now set your Multimeter to 2000 Ohms
put one lead from the meter, to the green wire from the Stator
and the other lead from the meter, to the Black w/red striped wire from the Stator
it should read around 380 Ohms


if both of your readings are close on these, then your Stator is ok

 

[DANNYGEALE]

ive decided too sell it as parts on ebay its jus too much work for me