Howdy folks, back at with the my 1981 KZ440 LTD if you've been following the excitement of this bike. This time, I'm trying to replace the oil in the forks.
I drained all the oil out, and when I went to take the caps off the forks on top I couldn't get them out. They are the circlip-type caps and I did remove the circlip, but they just won't come out. I can compress the caps, and they do move freely downward, but they seem to just hit a stopping point before coming out. Am I missing something? Also, they are not the air forks that the 1983 model got. Thanks folks!
Damn, that would be a really good idea actually. The only problem is that I'm away at school, and don't have a compressor or a jack stand to get the front wheel off to take the forks off. Thanks anyway though!
I would loosen the upper triple tree clamp & spray some solvent or penetrant onto the fork caps to clean them. guessing there's probably crud around the fork caps. or maybe the o-rings have hardened. heat might also help, but you'd have to remove the forks. For stuff like this I use Liquid wrench silicone spray lubricant or LW penetrating spray. Keep in mind that the fork caps are under spring pressure and could go flying & get you in the eye.
If you can get some pressure fuel hose clamped to the fork drain port and also to the nozzle on a bicycle pump (floor-stand pump, foot pump or the 12v kind), you should be able to pressurize the fork leg. You don't need a large volume of air; you just need enough pressure.
I'd put a cardboard box over the top of the fork leg to keep the cap from going flying across the parking lot. And maybe do it on grass, so when the cap falls down it doesn't get dinged-up.
You don't need a special stand to raise the front end: for day-to-day stuff, I pull up on the front and wedge a 2x2 or a section of PVC in as a brace. For a steadier support, you can then put about 9.5 inches of wood blocks under the case, and remove the brace.
I have also wondered if it would be possible to somewhat clean a fork leg just through the drain valve: drain out the old oil and measure, and do the same for the other fork leg; then turn the leg upside down, add a few ounces of diesel using a dental syringe, and shake; drain the diesel (maybe repeat until it comes out mostly clean), and add a few ounces of fork oil; shake & drain (the oil will have some diesel in it); then add the oil to both legs (as much oil as was in the leg with the most oil... plus a bit extra). My guess is that it may take a long time (days) for the diesel to bust-up the crud in the bottom, unless you have the fork legs in the tailbox on the back of your other motorcycle , as a sort of "ultrasonic cleaner" .