fork oil change 81 KZ 650 SR

I feel very stupid asking this but here goes ..

the forks are reassembled and put on the bike after i change the fork gaskets . wheel is back on - all is good ...

except there is no oil in the forks .. for some reason i thought i could fill oil thru the top once i unscrewed the airvalve cap thing - that hole is tiny - and i suspect also that it is only air supposed to be in there ?

do i really have to remove the forks from the bike to change the oil ? ?

i've tried studying the clymer manual - but i'm having a hard time figuring any other way than total disassembly (which would suck if thats the case )

anyone ... `?

(tried searching the forums but most forks are 70ies without the air thingie )

Can anyone say if my bike share forks with the 1981 CSR ? kawasaki.com don't show my model ...

i'll treat this thread as my personal thinking out loud notepad ..

i'll loosen the upper and lower fork clamps - then push the forks up .. fasten the clamps . then unscrew the fork cap with the airvalve on it ...

thats what i figure is what one is supposed to do ...

del

thank you thank you thank you it is correct i got the center axle - but i hope and suspect the rest is pretty much identical ... can't wait for the kids to go to bed, ouch sounds bad , so i can fix the bike

sometimes some things are easier said than done - so i decided to remove the forks - flip them upside down, remove the allan bolt that holds the piston in place and fill the oil through that hole. a baby bottle and a small funnel worked perfectly. then i applied a new copper washer and some threadlock to the bolt and refitted.

now the forks are again shiny and fitted on the bike . . but now one last challenge remains .. filling air .. manual says 8 - 13 psi in the forks .. how do i fill that tiny space with so little air that the pressure dont skyrocket ? the gas station pumps can't handle such low pressure with their new systems fitted ...

what do you guys use `? i've seen footpumps but they aren't very accurate .. and i'm afraid of blowing the gasket ..

feel free to comment

Hmmmm, interesting way of changing the oil. I've added fork oil to my two bikes just by unscrewing the endcap while they were attached to the bike. You can also measure the depth of the oil that way to determine if they are over or under filled.

My 750 is really touchy with the air pressure. The best way I've found is a footpump and digital pressure gauge. I like them around 10 psi, so I'll feel them to around 13 or so on the footpump gauge, then check it several times which drops the pressure down to 10 psi.

do you lower or heighten the forks before you unscrew the endcap ? because this was the issue i was having with the forks mounted - that i couldnt friggin move it up nor down and thus not getting the cap unscrewed.

it didnt take me more than half an hour to change oil on both sides - but it would be nice in the future do do it without all the hassle of torquing everything in place

Uncertain whether applicable in this case, but am thinking the bolt in the steering stem head top clamp (that clamps around the fork tube) must be loosened before the top fork cap may be removed.

Good Luck!

The Factory manual shows having the top cap flush with the top clamp which would definitely make getting the top cap off the fork tube a PITA. I set the top of the fork tube even with the top clamp so I can then get a wrench on the top cap. We're only talking 1/4"-1/2" difference so I can not decern any handling differences.

Like Patton suggested, loosening the top clamp helps make sure the topcap threads aren't bound by the fork tube.

i loosened both the top and lower clamp - but on my bike the top of the of the tube is to be set 2mm from the edge of the upper clamp - thus having a great grip on the cap.

patton - yes - i would imagine it would have to, and thats what i've been doing

i might do what you say link - and mount it just above the top clamp next time. that would def. make it easier


As you can all tell i'm new at the bike thing - and i do appreciate all feedback i'm getting

- last question - is it hard to get the cap to thread correctly when fitting it ? with the spring causing tension i mean ?

HansNOR wrote:

i loosened both the top and lower clamp...
is it hard to get the cap to thread correctly when fitting it ? with the spring causing tension i mean ?

It is sinfully easy to strip the ultra-fine soft male cap threads by getting it cross-threaded when attempting to begin screwing it into the steel female threaded tube top.

Probably better methods, but I use a large socket to press the cap down against the spring to initial contact with the tube, then very carefully -- aligning by sight and feel -- get the cap started into the tube with the threads properly aligned. Sometimes it takes several attempts to get it started just right. And when it starts right, it's usually easy to tell.

And BTW, when loosening the top cap, am thinking the top fork tube clamp should be loosened, but the lower fork tube clamp should remain tight to prevent the tube from turning as the cap is being turned.

As to pressurizing the air-assisted forks, on dirt bikes I use a bicycle tire hand pump (instead of a foot pump), if that makes any difference. The main idea being not to blow the seals with air compressor psi.

Good Luck!