2001 YZ125

Your compression must be bleeding out through the power valve vent tube. Pinch that thing off some how and the bike will start right up.

And away we go













Part 2

She'll start right up!

You need to ask the Pipe, Moto814, or William.... go to the Vintage Section

take spark plug out and have a friend kick it over while you put your thumb over spark plug hole. it should blow your thumb off... if it doesn't... you don't have enough compression.

c'mon rat... this kids been through enough... bought a bike that doesn't even run.

ok: ill try:

does it sound like it wants to kick over at all or is it just a dead kick? if its just a dead kick, take the spark plug out of the cylinder and put it back into the plug cap. turn off the lights and hold the spark cap in your left hand and use your right hand to push the kick start down. while doing that, hold the spark end of the spark plug close to the cylinder. if youre getting a spark then you will see it arc over from the plug to the cylinder. if you dont have spark then you need a new electrcal harness or CDI unit.

if you have spark, are you sure the carb is getting gas? is the petcock turned to allow fuel to flow? is the fuel line clogged?

is the air filter clean and allowing air flow? whats your fuel mixture? 32:1? how old is your fuel?

if you no longer have compression, but you had it before, then you didnt tighten down the bolts the way you were supposed to. you cant just crank them down. theres a science to it....id guess you have a bad air leak now.

thats all i got without having the bike here....

DISCLAIMER: IF YOU HOLD THE SPARK END OF THE PLUG AND GET ZAPPED WHILE PUSHING THE KICK START..WELL..DARWIN IS TRYING TO TELL YOU SOMETHING AND I TAKE NO RESPONSIBILITY

William knows two/ four strokes. Your in good hands with him.

Did you really do a compression check ? If so, How much?

the first time i ever redid my top end, i kicked about 500 times. it finally started but i had a air leak. spray a tiny bit of starter fluid into the reed cage or into the spark plug hole and replace the plug then start kicking.

is it a new plug? is it the right temp plug? br9 something? some bikes dont like br8's.

Ok, guys flame away... i'm done.

This has got to be a joke profile.

when you tore it down, did you notice if the piston ring was on correctly with the split to the back?

Didn't you say the guy told you he just put a new top-end in the bike when you bought it? Did you notice how easy the kick start was to push down, or did you run the bike at all before you bought it?

he didnt run the bike before he bought it. and read this guys profile. i think williams is right...so i too got taken hook, line and sinker...

You got ripped off if that is your bike .

Definetly BS.

Don't listen to these dumb asses.
Go to the dealer and get a first over powerband.

Take it apart again and take some CLEAR pics of the "new" top end and post them here. Lets see how new this top end really is.

I ran tiddler YZ's from 96 to 00....... I could fairly easily start them by hand on the kickstarter...

I'm assuming you did the spark test by putting the plug close to the cylinder and cranking it over.... and you say you have spark...

How do you know you are getting fuel? how did you tested that??

btw.... my preferred starting method for those years of YZ's when cold was always- full choke, no throttle... always easy starters...

lastly..... does it sound like it wants to start even the tiniest bit??

If i had to guess, I'd guess you have a fouled plug...