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2003 kx250 main shaft

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Recently bought a 03 250. Installed new fmf silencer with a gold fatty. Starting leaking at the pipe and silencer junction. So i checked the jetting. It's stock. So I'm waiting on a jet kit. My question is. I pulled the main shaft cover and its covered with a small layer of oil. Am I supposed to be able to pull on the main shaft with ease. Back and forth I mean. Seams its binding a little bit. Not sure if the power valve needs to be clean or if its stuck open. What would it do if the power valve was stuck open. Symptoms? Thanks in advance!!

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By "main shaft" do you mean crankshaft? If so, then yes, a small amount of end play (in and out) is normal. Radial play (up and down, side to side) must be zero.

If the powervalve is stuck open, the bike will have poor low-end power and sluggish throttle response at low rpms, and then an abrupt massive surge of power in the middle as it comes on the pipe. The '03 has very good low-end power and a fairly smooth transition onto the pipe when it's running correctly, so a problem will be obvious.

It's easy to check the powervalve operation. Just remove the access cover and rev the engine, you'll see the linkage move in and out.

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no you should not be able to pull that in and out. might be missing the circlip at the end that holds rod in place. should be a circlip then a roller with a groove that the water pump govenor rides in and then another circlip that holds those in place.

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