Dirt bike died and wont start! What is it?

I was riding it one day and it shut off and when i kick start it, it only has a little bit of compression and it backfires when its being kicked, what is wrong with it? i dont think anything broke in the engine because nothing broke when it shut off.. its a 99 kx 125, it has spark and enough compression to start.. it just wont

do a real compression check with a gauge "and try what ive sugested" before you go buying parts


if its any more then 10lbs lower then the manual specified for normal compression id assume it needs work

but from what you describe iit could be a load of things
a. broken a ring. "it would have a great loss in compression"
b.burned a hole in the piston "praticaly no compression"
c its got a weak spark "but usualy that just dosent happen out of nowhere" and you say it has good spark
d its got a carb problem
e its out of gas.

pull the gas line off the carb and see if you even have gas coming from the line
if you have an in line filter it might be clogged
.. there is a strainer filter in the tank too on the petcock,
if gas comes out of the line .. then put it back on the carb ...

then try to open the screw on the bottom of the carb bowl .. it is next to a little hose coming off of the bottom ..... if gas dosent dump out of it or it barely barely trickels your float is sticking

Sounds like carb problems

ck air filter also

A little comp but enough ????????????

If the compression dropped dramatically, you burned a hole in the piston is my #1 Guess.

Let me get this straight..... First you said it has a "little bit" of compression... Bu then it has enough compression?
Sounds like you have a bit of water in the line, or may need a new spark plug wire. Try using some dry gas and/or replacing the spark plug wire. Could also be a bad carb. try taking the carb off if those two things don't work and replace or rebuild it.