New fork oil level weird!?

[polkat]

Okay, I rebuilt my '82 KZ750H forks with the good help of folks here on this board and others. Then I went to fill them with oil. My manual says to start with about 280cc's of oil, then measure the distance from the oil level to the top of the tube. The book says it should come in at 436mm (+/- 2 mm). I made my measuring rod indicating the top of the fork tube, the 436 mark, and made it about 40mm past the 436 mark so I'd have some indicator of where a too low level was.

Testing the level, the rod stayed dry!! The book says that the forks should be fully extended during this test. Is that wrong? I assume this is the original KZ750H fork, but have no way of knowing. I'm hesitant to put more oil in.

What am I doing wrong? Thanks!

[bross]

Originally Posted by polkat

Okay, I rebuilt my '82 KZ750H forks with the good help of folks here on this board and others. Then I went to fill them with oil. My manual says to start with about 280cc's of oil, then measure the distance from the oil level to the top of the tube. The book says it should come in at 436mm (+/- 2 mm). I made my measuring rod indicating the top of the fork tube, the 436 mark, and made it about 40mm past the 436 mark so I'd have some indicator of where a too low level was.

Testing the level, the rod stayed dry!! The book says that the forks should be fully extended during this test. Is that wrong? I assume this is the original KZ750H fork, but have no way of knowing. I'm hesitant to put more oil in.

What am I doing wrong? Thanks!

That sounds backwards, any forks I have done have always been fully compressed, spring out, measure your level. But the 436mm sounds like it would have to be extended. I just did the forks on the Bonneville and Scrambler and they were set at 143 and 120mm.

Go ahead and add oil, you can't hurt anything and if you over fill, just tip it back out.

[StarGate]

Your manual should give 2 different measurements for the amount of oil to put in each fork. One is when changing the oil the other is for when they are completely dry as they would be from replacing the seals. Are you using the correct one for the amount to put in?

[MagicNinja]

I don't know if it would help but when I change my fork oil I pump the forks several times to get all the air out of them when adding oil. The first couple of pumps they feel spongy until you get all the air out of them and they compress smoothly. If I remeber right I couldn't get an accurate level reading withouth pumping.

[polkat]

Well, don't I feel stupid! Found a supplement in that back of the manual that gives different (larger) amounts for changing (290cc) and dry (308cc) in '82 LTD's. I'll try that and if it works I won't post one this one again. Thanks for all the advice!

[kawpaul]

A better way to do it is to just pour plenty oil in and work the fork to get the air out. Then take a syringe with a hose that reaches to the correct level and draw out the excess.

[bross]

Originally Posted by kawpaul

A better way to do it is to just pour plenty oil in and work the fork to get the air out. Then take a syringe with a hose that reaches to the correct level and draw out the excess.

That's what I used when I did the forks, Motion Pro Fork Oil Level Gauge



but a stick works just as well.

[kawpaul]

That is a nice gadget but I already have a syringe I picked up at wally world in the gas can section. And I got some clear hose as I picked up some for a manometer. Would be logical to just build a depth gauge to go along with it since I will be replacing my fork seals next week anyway.

[wdhewson]

I think that I had a similar problem when I re-did the forks on my 1981 KZ550A2. The specified volume of oil did not correspond well with the "stick level". I honestly forget what I eventualy did, but probably relied on the volume, which seemed ample considering the fork design. Has anybody had good correlation between added volume and "stick level"?