My 2005 Kawasaki KX 125 was running fine, went riding came home and went to ride today and it wont start. It started for a few seconds but the second you gave it any gas it bogged and died. Now it wont start. What might it be?

for kx125, that kind of problem i kind of remember my friend just like that too. so clean everything inside . so u have to changes the valves and also the lifter then do the piston pin too,.also chick the rod if in good! that's it for now then when u do that tell me what going on!

could be a jettng problem or a sign your rings are starting to wear out. have you noticed any loss in power? try running a compression test.

sounds like you need to rejet the carb..

Check for spark, compression, replace plug.

If its running for about an hour before trouble,there is not a lot wrong.Have a real good look to see it has the correct spark plug.This doesn't mean the original type but by looking at the plug and its colors it may be the wrong heat range.This is often the case with different styles of riding and any mods done to the bike.Next ride,take another plug with you.When the bike stops,put the other plug straight in and see if that gets you going.This would be the 1st place to start looking for the fix to your problem.Hope this helps

sounds like too much oil in the mix add more gas & clean spark plug
Cheers Rob

Remove the slide from the throat of the carb, move the clip on the jet needle one notch lower. This will richen the low end fuel/air mix. - - - Simple, quick, and free.

Do it, then rate this answer as "Very Helpful". Thanks.

when riding try pulling choke u p and see what happens

is it getting fuel? try tipping a very small amount of fuel down rhe plug hole, replace the plug if it fires you have a carb problem.