Hi all. Been lurking a long time and just bought a used KLX250 a few weeks ago. This forum was a huge help in deciding to buy the KLX and has been great reading. Anyways, love the bike, but wanted to drop to a 13-tooth countershaft sprocket ... had the same troubles others have had, so I cooked up a little removal system. After carefully tapping the washer flat, I:

1. Mounted old rear sprocket (new one, in wrapper, came with bike) to an 8' 2x4 and used it as a lever running from under the rear shock mount to over the rear axle and back, where a friend held the far end steady. No need for downward force, just a steady hand to counteract the force of my wrench against the countershaft.

2. Put breaker wrench with 4' breaker bar extension on countershaft.

3. Careful, consistent force up broke the nut free with very little effort in a couple seconds. This after lots of force was used to no avail beforehand. Tried other approaches, but this one worked well and with items I had on hand.

May not be the ideal solution if you don't have the spare parts or the wood, and because there are long levers involved, there's potential for breakage. Your mileage may vary ...

Photos here: http://picasaweb.google.com/fdubinge...rocketRemover#

Worked great, so I thought I'd share.

Fred
07 KLX250
06 Hayabusa
00 Concours

 

Nice! I like to see ingenuity on here. The pics are worth a thousand words too. I've tried different breaker bars etc and finally settled on an old garage sale impact wrench I have , that eventually gets the job done. Another good tip , on reassembly use a little anti-seize on the threads, makes it a little easier next time.
Thanks for posting it up.
Dan

 

When you put it back on just snug it up, then just fold the washer just enough for it to do it's job. Will make the next swap free of any "special" tools. Some anti seize or grease on the threads will help too.

If you didn't figure it out, completely derail the chain from the rear sprocket after you push the axle forward. Makes it so much easier to fumble the sprocket in place.

 

So why didn't you just use an impact gun? Is this for the non-air tool guys? Is the countershaft sensitive to air tool impacts?

 

Sounds like you found a good way to remove the old countersprocket. We tried everything, then remembered that we have a cheap impact that plugs into a car cigarette lighter. It's kind of an emergency device for chaning flat tires quickly on the road. We didn't know if it would actually have enough power to remove the nut, but it did instantly. Here's a pic:

http://www.amazon.com/gp/product/ima...&n=228013&s=hi

 

Highbeam:
I don't believe the countershaft is particularly sensitive to impact tools. I am in the middle of rebuilding my garage interior and it currently doesn't have electrical power so I just used the stuff I had laying around. It was nice using the 2x4 because it went right back onto the woodpile when I was done with it. (Most people probably won't have trouble with the nut once it's broken loose the first time, so it isn't necessary to keep anything special around just for this job.) I mainly wanted to offer the setup for those having trouble with the nut who may not have other options like an air or electric impact wrench.

Fred

 

Gotcha. The picture really helped explain the setup.

 

Thought some of you might be interested in the following:

The text below is from the 09 service manual.

09 SERVICE MANUAL
"Engine Sprocket Installation
• Replace the sprocket washer with a new one.
• Install the engine sprocket so that stepped side [A] faces inside.
• Apply molybdenum disulfide oil solution to the threads of the output shaft and seating surface of the engine sprocket nut.
• Tighten: "

"Torque -Engine Sprocket Nut: 125 N•m (12.7 kgf•m, 92.2 ft•lb)"

By comparison for anyone who is not familiar with N.m.

09 SERVICE MANUAL
"Torque -Rear Axle Nut: 110 N'm (11.2 kgf·m, 81.1 ft'lb)"

Same as a wheel nut on most passenger vehicles.