I had a guy tell me today that I will constantly be changing fork seals on my 97 250SX. Does this guy know what hes talking about? I know they have to have the exact amount of fluid necessary, but are they going to cause me headaches? Thanks for any advice.
These forks are subject to leakage at a higher than average rate. However, the problem can be corrected with the use of fork boots. I like the neoprene type. The "bellows" style will reduce air flow to the radiators. Seal failure in these forks is primarily due to dirt getting caught under the lip. A condition common among conventional forks. Often a seal can simply be cleaned and returned to service. I know of several of these Zokes with frequent leakage problems that have been resolved only after the use of boots. Now all you have to do is rework the slot on the damp tubes, slow down the high speed rebound, and increase your spring rate and you will have an awesome fork.
Wayne - The problem isn't the fork boots. It's the forks themselves. The 'zokes that are on your bike are almost identical to the ones on my GasGas, except for the valving. The problem lies in the lower tube. The aluminum that it is made from is very soft. During operation the aluminum wears, contaminates the fork oil and eventually plugs up the valving. It's also one of the causes of leaking fork seals. The other one is dirt contamination from the outside. Periodically you should lift up the fork boot, or neoprene "seal saver" and blow off the dirt lying on the dust cover. Make sure you dust cover isn't brittle and still fits snugly around the fork. Periodic maintenance is the key to keeping the 'zokes in working order. To reduce fork oil contamination I had the lower tubes hard-anodized by MX-Tech. I recommend you change fork oil immediately and do this on a fairly regular basis.
I think the guy telling you that the forks aren't good is pretty clueless as to how well they actually work when setup properly. Sure the fork seals CAN be a little annoyance but it's not a major issue as long as you check them from time to time, get some form of fork boot on them, and change the fork oil on a reasonable basis. (commercial mode on) and if you want to see how totally AWESOME these boingers can be send them to MXTech for a little work and I promise your will be blown away.
Patman & woods... are right (IMO) those are great forks. 50mm WP's on KTMs have a bad reputation also. I have 2 1/2 years, and 3300 miles on my original fork seals (never replaced, not leaking). The key is mainenance. Do as Woods... says, along with fork boots, or fork booties and you will really enjoy the ride! Have Fun!!!;)
Most suspension shops offer hard anodizing service for under $100. The forks must be disassembled though. I used Jer at the time because his shop was just up the road. He also delivered them to my house when they were done. Hard anodizing allows you to go longer between fluid changes.
Performing regular maintenance and keeping dirt away from the seals is the key to preventing leaks.