pit bike wont start after piston change

[dowierasta]

hey,

so i just changed the piston and rings on my 125 pit bike 4 stroke and put it all back together to find she wont start at all, there def a spark and if you really go for it it starts and makes a weird noise for a bit then chucks out what i assume is exhaust fumes out of the air filter. Im guessing the valve timing is out but would really appreciate a gudie or tutorial from someone in the know. Ive tried changing both the camshaft and camsprocket positions but with no success.

cheers

[swifty]

You Tube

You Tube

[dowierasta]

Originally Posted by swifty

http://www.youtube.com/watch?v=_2xRn...eature=related

http://www.youtube.com/watch?v=QJciyJRJh8Q

looked at these videos but bike still wont start, also for some reason today there is no longer a spark (fukin chinese **** lol)

[eoinm145]

make shure the head gasket sealed up right

[dowierasta]

Originally Posted by eoinm145

make shure the head gasket sealed up right

what do you mean sealed up right, and what difference would it make?

[dowierasta]

Originally Posted by dowierasta

what do you mean sealed up right, and what difference would it make?

please ppl any more insight?

[turbocrow]

Originally Posted by dowierasta

please ppl any more insight?

You need a spark so its the electrics

[dowierasta]

yer i dont get it tho i changed the ignition coil and the stator quite recently, could it be anything else which is causing there to be no spark?

[physco_nutcase_danny]

Originally Posted by dowierasta

yer i dont get it tho i changed the ignition coil and the stator quite recently, could it be anything else which is causing there to be no spark?

c.d.i unit and pick up sensor on the stator may need adjusting.needs an air gap between the pickup and flywheel magnetic strip of about a rizla carboard packets width.

[dowierasta]

Originally Posted by physco_nutcase_danny

c.d.i unit and pick up sensor on the stator may need adjusting.needs an air gap between the pickup and flywheel magnetic strip of about a rizla carboard packets width.

thansk for all replies so far, yer checked the little magnet thing on the outer flywheel against the stator pickup and it seems fine. Il try and list all the probs + work done so you guys can get a better picture

previously
new stator
new ignition coil
all wiring seems ok

new piston and rings done, fucked up valve timing and tried to correct it. Got a few blips of life but it didnt sound right and smoke was coming out of air filter and other parts. Tried to adjust valve timing again and again

Eventually no spark and kick starter is really easy to push down, checked compression with thumb over spark hole and there is virtually none

thats pretty much it, will lone out my gf to the guy who helps me sort this out lol