Now my Kx 125 Won't Start :(

[TaKeN]

Going on from this thread Here >> http://www.kxriders.com/forums/index.php/topic,2615.0.html


Which became untidy,


I took the KX out this saturday with a new plug in the bike ( NGK BR9EIX ) the new plug made no difference and the bike was miss firing as usual, so i took it onto the yard and rev'd it up and down the see if the plug was fouled.

I got annoyed with the bike, pressed the kill switch , turned off the fuel stop and then put her away.


Later on ( Saturday evening ) I decided to check the air filter, it seemed a little oily but not to bad, i took it out then proceeded to remove the carb.


I disconnected the main fuel line to the card, undid the two clips that hold the carb between the air box and the reed intake area, then removed the main slide with the needle

I pulled out the carb then stuffed some blue towel down the rubber intake pipe that goes to the reed valve to stop any dirt from getting in.


I then took the bottom off the carb and blew compressed air through all the visible holes in the carb.

After i did this i put the bottom back onto the carb and then put the carb back in the bike. I connected everything i had removed and reinserted the main slide and needle, Making sure the needle went back into its hole.


I turned on the fuel tap , put on the choke, tryed kick starting the bike several times with the throttle wide open and it wouldn't start.


After trying and trying for ten minuted i decided to clean up the old spark plug ( B8EG ) and put it back into the bike, The BR9EIX was very wet because i had flooded the bike.

I put the old plug back in and kicked away at the bike but once again she wouldn't start,

I tested the plug against the Exhaust and there is a spark ( I forget this might damage the electrics )


I don't have a compression tester so i jammed the throttle wide open and leant the handle bars against the wall so the throttle stayed open, i placed my thumb over the spark plug hole ( with the plug removed ! ) and used my other hand to push down the kick start.

There is some compression because it blew my thumb off the hole with a healthy * PAP *


I left the plug out and let the bike sit overnight to let any excess fuel evaporate from the cylinder.

This morning i tried the bike again with the plug in but she still won't start,


I don't know whats going on, Could i have blasted some dirt even further into one of the jets ?


Any advise would be great gents, i'm beggining to wish i'd bought a CR 125 instead of this KX, Its doing my head in.

[FPMXer]

Taking the carb out and removing the bowl, then blowing air through the open holes is doing you no good. You have to remove the jets, screws and anything else that can be removed, then spray all the holes, ports, interior and exterior with carb cleaner, then follow that with compressed air. Once you feel air coming out of all the jet holes and everything, pick up the pilot jet and see if you can see light through it. Most of the time the pilot is the culprit to a non running bike. Spray it out with carb cleaner and then compressed air. Once the pilot and main are free of trash and you can see light through them reinstall everything and put it back in the bike. When the bike is cold, pull the choke open and leave the throttle closed, it should start within a few kicks. If not then turn the idle screw in a few turns. Trying to kick the bike WOT is only flooding the engine. There is no reason to kick the bike with WOT. Try this and it should run.

[TaKeN]

Thankyou. I will report back

[TaKeN]

Thankyou very much buddy.


I removed the carb, took off the two jets and left them in carb cleaner for 10 mins.


Whilst they were soaking away i blew the carb completely clean through with the air compressor,


Whilst i was cleaning the air screw, i noticed it was turned out 5 1/2 Turns :O


IIRC, This should only be out 1 1/4 turns ?


Please can you confirm this...


After putting both jets back in the bike fired up on second kick with the throttle closed and the choke open ! 

[FPMXer]

I run my bike with the air screw out 2 or 2 1/4 turns. Good to hear she's running.

[TaKeN]

She's running but i realy think something is majorly wrong.


Its as if the jetting is wrong throughout the entire range, Missfiring constantly.


Im beggining to think it needs a new piston but it surely cant if it runs


Sorry i took so long to reply,

[blackkx]

 First off i want to introduce myself my name is Mike and im new here hello to all. 

The first thing i would do is get a hold of a compression tester and se where the motor is at compression wise , if it has good compression then you can start looking elsewhere to find the problem . keep us posted .

[TaKeN]

Thanks Black, i will get a compression testing guage and report back.

[gowen]

She's running but i realy think something is majorly wrong.


Its as if the jetting is wrong throughout the entire range, Missfiring constantly.


Im beggining to think it needs a new piston but it surely cant if it runs


Sorry i took so long to reply,

How do your plugs look after a ride? Is it pretty easy to start? Fire on the first kick?

[TaKeN]

After ive ridden the plug looks quite wet, its also more black than brown.


It starts on the second kick usualy but its very easy to kick.


When i tried my thumb over the plug hole to test compression it didnt blow it off.


But when i had someone open the throttle and kick the bike it blew my thumb off with a nice ** PAP **

[gowen]

Can you post up what size Jets you are running? Main Jet, Pilot? Though a compression check is a good start too. So, you might want to do one of those while at it.

[TaKeN]

I will open up the carb and have a look