Oil in forks?

polkat wrote:

Okay, I'll give her a try. Oh yea, should the upper fork clamps be loosened to do this?

YES -- The upper fork clamps should be loosened before attempting to remove the caps, and should also be loose when installing the caps.

On some bikes, the caps are almost impossible to unscrew without first loosening the top fork clamps.

Good Luck!

Mine has the drain plugs on the sides of the forks. Remove them BEFORE you jack the front end up and use the handlebars (up and down) to pump the oil out of the forks. Then jack it up and take the tops off and refill the oil. If the oil is really dirty, fill it and button it up and pumpp it for a while and drain it again. Some of us folks get lazy and don't change the oil for a long time...

polkat wrote:

1982 KZ750H. How does one put oil in the forks, how much, and what kind?

The best oil for my 750 is the 15W fork oil. Bel Ray is good. Don't use motor oil, the viscosity ratings are not the same.

Got the oil out. Man, came out looking like some old grey substance! I doubt it was changed for some time. My manual says to use 10W oil, doesn't say motor oil or anything else. But you're saying motor oil is a bad idea?

Also, the manual says to use "liquid gasket" on the bleed screws and reinstall them with their gaskets!? Neither screw had a gasket! They weren't leaking though. Can I assume that "liquid gasket" means something like Loc-tite? Or can I just spread them with a little Permatex #2?

Mine did the same thing. I'm glad I wasn't standing in front of the port when I pushed down on the fork. It spewed out about 6 ft and stuck to a table I had leaning against the garage wall:


I put in 10W like the manual said and it works fine. I think that next year when I change it again, I'll try something a little heavier like 15W. I just used some RTV liquid gasket on the screws and it sealed great.

Have fun!

polkat wrote:

Got the oil out. Man, came out looking like some old grey substance! I doubt it was changed for some time. My manual says to use 10W oil, doesn't say motor oil or anything else. But you're saying motor oil is a bad idea?

Yes, you need real fork oil. All bike shops have it.

polkat wrote:

Got the oil out. Man, came out looking like some old grey substance! I doubt it was changed for some time. My manual says to use 10W oil, doesn't say motor oil or anything else. But you're saying motor oil is a bad idea?

Also, the manual says to use "liquid gasket" on the bleed screws and reinstall them with their gaskets!? Neither screw had a gasket! They weren't leaking though. Can I assume that "liquid gasket" means something like Loc-tite? Or can I just spread them with a little Permatex #2?

I think blue loctite would work, but the typical silicone rubber gasket maker stuff will also work.

Link14 wrote:

Mine did the same thing. I'm glad I wasn't standing in front of the port when I pushed down on the fork. It spewed out about 6 ft and stuck to a table I had leaning against the garage wall:

Everybody does that the first time. Second time, wrapa paper towel around to cover the hole and tape it to hold it on the fork while you pump so the floor won't be covered in oil.

I have what is supposed to be the actual shop manual (Kawa), but it's a copy someone made for me and the pics in it are poor.

Link14, when you say 10W do you mean engine oil? The manual doesn't specify a "fork" oil. What would happen if I just used 10W? (I already have 10W and I'm poor) !

polkat wrote:

...The manual doesn't specify a "fork" oil. What would happen if I just used 10W?...

I believe the Fork Oil table in the Scheduled Maintenance section implies that you're supposed to use fork oil. One of its attributes is that it's non-foaming.

Okay, new problem. I got the caps off and pulled the springs. Everything that came out was covered in a gray sticky mess, almost like a light axle grease the same color as the nasty gray oil that came out when I pulled the bleeder screws. Frankly, I don't think in the 28 years of this bike's life, the forks have ever been serviced. There was no air in the forks when I tried to release it.

Anyway, as I do not have the tools to disassemble the tubes, is there any kind of flush or solvent I can run through them that won't hurt the rubber seals? Thanks!

I used a small amount of the fork oil to flush the fork tubes. You can also take a wire coat hanger, make a loop on one end and attach some paper towel to the end. Stick it down the tube leg and swab it around,you will be surprised at how much aluminum dust (grey slime) and crud will come out of those tubes. Just don't lose the paper towel down the tube.