Exhaust valve removal & clean up

[duckunter]

I am trying to disassemble my exhaust valve so I can clean the carbon from it. It is a 2000 KX 250 and I would guess it has never be taken apart and cleaned. (not the original owner!) I can't get the idler gear or secondary exhaust valves out of the cylinder block. I'm sure they have a lot of carbon built up on them. Any suggestions on how to get them out without tearing up the metal on the shaft of the gears??? If I scar the metal and file it smooth again will it hurt anything? Open to suggestions.

[2stroke173]

The clymers manual for my bike says "If you must use force to remove them, first wrap the shafts with a piece of shim stock (not sure what that is) or similar material. Doing so may help prevent damages to the shaft surfaces."

Maybe you can use compressed air and direct it to the exhaust port for the secondary valves (where it opens and closes port) and that will pop them loose...I just removed, cleaned, lubricated, re-installed the exhaust valves on my 93 kx125

[#34 KX 250]

i agree with 2stroke173

[condon66]

Shim stock is very thin metal sheet. It can be bought in varied thicknesses like .003 or .010. We use brass shim stock when needed. The idea in the Clymer manual is to wrap a piece around the bottom of the exhaust valve so that you can grab it with a pair of pliers and tug. The shim stock prevents damage to the surface and is flexible enough to wrap around the valve. Just keep working at it and be patient. They will come out.

[duckunter]

Thanks for the input! I let some engine degreaser soak in/on them for a few hours and I was able to pull them out. (with vice grips)