1989 YZ250 Front Spring Replacement

1989 YZ250 Front Springs for 200 lb Rider

The front springs for the 1989 YZ250 are becoming just about impossible to find. The stock spring was for a 155 lb rider if this is not you it can be very hard to find the correct spring. The stock front spring has an overall length of 505mm and a diameter of 35.8 mm. It has 43 coils and a wire size of 4.6 mm. The stock rate was .379 kg/mm. I figured that for a 200 lb rider I would need a rate of .447 kg/mm but this was not available for the 89 yz. I did a lot of searching on the Race Tech site and found that the front spring for the 1997 KDX200 will fit the 89 YZ. The KDX spring is 472 mm long and 35.8 mm in diameter and it is available in a .44 kg/mm rate. I would need to make a 33 mm spacer. The Race Tech part number is FRSP 364744 and the springs came complete with a section of tubing to use as a spacer.

I removed the fork caps, remembering to loosen the top clamp bolts first. I slowly removed the stock spring so that most of the oil would remain in the fork. After removing the springs I tied a long piece of safety wire around the damping rod so that I could later pull the rod up inside the spring. I checked the oil depth, 125-165 mm, and added a little to make up for what came out with the spring. Now would be a good time to change the oil but I had just a few weeks ago so it was not necessary.

I cut of two sections from the supplied tubing and filed them to 33 mm. I carefully slid the new springs over the safety wire and then the spacers. I used the safety wire to pull the damper rod back up and then started the damper rod threads into the fork cap before removing the safety wire. It was then a simple matter to rethread the fork cap to the damper rod and tighten the jam nut to 14 ft-lbs. Remember to start with the jam nut 18 mm down from the top to make sure that you get good thread engagement. Torque the fork cap to 20 ft-lbs and the pinch bolts to 17 ft-lbs.