i haven't, but the forks aren't too hard to remove, and a great time to change the fork oil. if your interested in doing some maintenance, this may help, taken from our technical section
It's easy, but a bit time consuming. If yours have never been done (most haven't) drain bolts or not you'll want to remove them from the bike and give them a thorough dump and flush. Prepare a container for the used fork oil and the oil you'll use for flushing. You're probably going to need to flush, refill and dump your tubes at least a few times until they're clean.I like to use a trash can with a hefty bag liner. Contains a lot of the mess and gives you plenty of operating room. You'll also need something to flush the fork tubes. I use cheap, house brand ATF. Some guys use kerosene or mineral spirits. I prefer to do it with ATF, but whatever you use make sure you have an adequate quantity for the job on hand. I like to have at least half gallon handy. You'll also need a ruler that reads in mm's and is narrow enough to fit inside the fork tubes.. Preferably in a light color so that you can use it as a dipstick and can easily see the oil level.
Admiral has an excellent writeup on completely disassembling the forks in the stickies. I'm not gunna duplicate his work here, but you'll have to judge for yourself whether the sludge in your forks warrants full disassembly. I highly recomend it but on newer bikes or older bikes that have had their forks maintained regularly (yeah, right) you can squeak by with a simple flush and refill. Ok, it ain't so simple, but at least if you have an early bike it will be a cakewalk AFTER the first time. More on that later. You late model losers gotta do it the hard way EVERY time. Send a NastyGram to Yamaha.
This is pretty much the basic procedure for setting the forks to stock spec, with no fine tuning:
1. Lift bike with front wheel off the ground. You want to lift the bike in a stable manner and have it stay put. You're gunna be removing your forks, so use a bike lift or a really solid platform under the engine.
2. Disconnect brake cable (drums) unbolt caliper (discs) and tie caliper out of the way.
3. Undo speedometer cable and remove front wheel. Remove front fender.
4. Loosen the pinch bolts on the top triple, then loosen the fork caps at the top of the forks. You want to do this first while the lower triple tree pinch bolts are still tight to keep the tubes from spinning. You'll see a slight chamfer at the topsides of the upper and lower triples around the holes where the fork tubes pass through. Put a few drops of oil in each of the 4 chamfers. Later on it will ease removing the fork tubes and reduce the chance of scarring the tubes.
5. Loosen the lower pinch bolts. Lightly tap the triples with a rubber mallet to allow the oil you applied to make its way between the triples and the tubes.
6. If you're golden, the tubes will slip out of the triples easily, or with a bit of twisting and tapping. Be patient and let the oil do its job and in most cases the forks will slip out of the triples without spreading the pinch clamps. Spreading the clamps should strictly be done as a last resort.
7. Remove a fork tube, then finish removing the fork cap. Then, over your trash can remove the spacers and springs. Your oil will resemble thick gray mud and this will most likely be coating your springs. It can make quite a mess.
8. Holding your fork tubes vertical, put about half a cup of ATF in them, then cycle the fork legs up and down a couple of dozen times, then dump them out. There will probably be gray gack in there, so fill, cycle and dump until you're getting nothing but sweet red ATF with no trace of gray gack when you dump them.
9. Once you're satisfied that the forks are completely devoid of any trace of the old crud and moisture it's time to refill them. I like to do this while they're still off the bike because they're easier to fill and measure and if you should happen to overfill them you can simply pour out the excess rather than having to pump it out. Some guys prefer to do it on the bike. Whatever floats yer boat is fine, but they both have to be measured accurately and they both need to be filled to the same level.
10.Holding the fork leg vertical with the lower fork leg resting on the ground and the fork tube fully COMPRESSED into the lower, measure out about 8 ounces of fork oil. Pour about half of it into the fork tube, then cycle the legs a few times. Add more oil slowly to each leg until your ruler tells you that your oil is 135mm from the top of the tube (again, measure with the fork COMPRESSED). Cycle the legs by hand a few more times to get the air out of them, then recheck your measurements. Once done, install your fork tubes back into the triple, tighten the pinch bolts in the lower triple, , install the spring and spacer and tighten the cap. Then tighten the pinch bolts in the upper triple.
The cap should be installed and tightened with the fork legs fully EXTENDED in order to keep your air gap. Don't wait until the wheel is installed and resting on the ground or all your careful measurements will have been wasted.
11. Install front wheel, reconnect brakes and speedo cable, but do NOT re-install fender.
12. Put the bike on the ground. Hold the front brake and cycle the front suspension by "bouncing" your front end up and down. Check cycling of the front end and make sure the front end cycles smoothly wih no signs of stiction, and THEN install the fender. If you bypass this step your fender bracket could lock your lower fork legs in an out-of-parallel alignment and your forks will stick.
Do this at least once a year and you'll only need a one-time, clean up flush and refill. Early model guys can accomplish it without fork removal. Just remove the the front wheel, drain the forks using the drain screws, add some flush oil, cycle by hand a few times, drain and refill.
I think I explained this elsewhere, but you don't change your fork oil because it wears out. There isn't enough heat or friction built up in your front end to ever wear the oil out. Theoretically it should last forever, no?
No. What happens inside your forks is that moisture from the ambient air collects inside the tubes. It gets aerated into your fork oil and emulsifies with the oil, forming the gray goo. Since there isn't enough heat in the forks to drive the moisture away it continues to concentrate, forming even more gray goo and eventually rusting your fork's internals until the orifice holes rust closed. It continually condenses and recombines within the tubes so in effect it's always raining inside your fork. The only way to slow the downpour is with new, dry oil, which will over time become contaminated all over again and require flushing and filling. This is a function of time rather than miles and it occurs at roughly the same rate whether you ride the the bike or not.
If you suspect you've waited too long and you're getting rust deposits or have what appears to be clear or rusted water in your flush oil along with the gray gack or id the bottoms of your fork springs are rusty it's a pretty good indicator that you'll need to completely disassemble your forks per Admiral's stickie and assess the damage.
Last edited by lizrdbrth; 09-09-2013 at 08:09 AM.