need help changing piston ring in an 03 kx 125

[race1251234]

i have an 03 kx125 and its boared out to a 150 or 155cc cant remember...but i need instructions on how to change out the ring on it.thanks

[DRGSin393]

You need to buy a round first... Welcome to

[crfjedi393]

Changing the rings is not that tough. Just act like you know what you are doing. Show some CONFIDENCE. After removing the old rings, start one end of each ring and just work the rest of the ring around the piston until it falls into place. Don't be overly aggressive with them but you can put more pressure on 'em than you might think. That is one thing I haven't taken pics of so take a few pics so you can post them for others if you've got a digital camera.

[race1251234]

i have an 03 kx125 and its boared out to a 150 or 155cc cant remember...but i need instructions on how to change out the ring on it.
or i should say what needs to be taken off to get to the piston and ring lol

[Henry]

Originally Posted by race1251234

or i should say what needs to be taken off to get to the piston and ring lol

drain coolant, take off tank, take out the spark plug, take off upper motor mount(usually connected to the head), take off the head, slide cylinder off, and your piston will be exposed, the rings are pretty easy to identify. i think thats it but if i missed something anyone please correct me.

[TUK101]

Originally Posted by Henry

drain coolant, take off tank, take out the spark plug, take off upper motor mount(usually connected to the head), take off the head, slide cylinder off, and your piston will be exposed, the rings are pretty easy to identify. i think thats it but if i missed something anyone please correct me.

Before you do any of this though, wash your bike real good. Get all of the built up oil and dirt off from it and wash it real good. And dont take out the plug until you get the tank off first, it will help to keep any dirt out of the plug hole. You dont want any dirt getting knocked into there and then falling into the bottom end when you pull the cylinder off. Also, I highly recommend buying a shop manual for your bike and reading it over real well. But here is how I go about rebuilding my bikes. So, 1st, wash bike. 2nd, take off seat and tank. 3rd, pull carb, drain coolant. 4th, pull hoses from cylinder head, again brush away any dirt and then pull plug. 5th, take off head, then cylinder. Now you have access to the piston and rings. You will want to wrap a clean towel around the crank before you pull any circlips, just in case one wants to fall into the crank.

[moto814]

Originally Posted by race1251234

i have an 03 kx125 and its boared out to a 150 or 155cc cant remember...but i need instructions on how to change out the ring on it.
or i should say what needs to be taken off to get to the piston and ring lol

Get a service manual for your bike. Read it.

If you still have questions after that, post them.

-Steve