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Discussion Starter · #1 ·
When changing the fork oil on my KZ750H3, first, a rough amount is poured down the forks and then the distance from the top of the inner tube to the oil level is measured. No matter what I use, be it a wooden dowl, a metal tube or whatever, it is difficult for me to see the actual oil level. Part of it may be my old eyes, but most oils are dyed a color, but when spread out thin, the coloring is nearly invisable. What tricks do folks here use to measure (see) it? I was thinking maybe paint whatever I use a flat white? Thanks!
 

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I guess I'm missing something here. You can't see the difference between the the part of a wood dowel that is dry vs. the part thats soaked in oil?
 

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Oils fluoresce under UV light. Look at it with a UV light, don't look directly at the light, only indirect. Don't want to sunburn your eyeballs.
 

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Discussion Starter · #4 ·
Yea, I can see what's wet, but when dropping the rod into the fork it almost always gets smeared by the inside sides of the fork, and there's no distinct line visable. I'll give the UV light a try, but the above might kill that idea. I've tried this several times, but trying to hold the rod so it won't touch the sides is difficult. Maybe I should try making a guide of some type.
 

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Discussion Starter · #6 ·
Nice tool, but the oil level spec on the KZ750H3 is 436mm below the top of the tube (fully extended). That tool wouldn't come close. The problem for me is that the thin spread of new fork oil on the measuring rod (regardless of the dye color) is basically clear, and therefore hard for me to see. I was thinking that I might paint the end of the rod I'm using a flat white marked at 436mm and see if that helps. Wadaya think?
 

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Then get something metal. Wood is just gonna soak in the oil. You can read a dipstick cant you? Its metal so the oil will stick to where it touches.
 

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Discussion Starter · #8 ·
Yea...I can read a dipstick. I'm using a metal rod now, but it's no go, but now that you've mentioned it, maybe I'll try an old car dipstick.
 

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My eyes struggle with dipsticks these days. With all the accurate fuel injection and improved oxidative stability of oils, and the lower viscosities now used, the oil on the dipstick is pretty thin and clear. This versus an old SAE 50 grade filled with black soot in the old days. So I've put a 500 Watt halogen bulb in the garage. Dipsticks will often have a cross hatch to hold more oil and made the "read" easier.
 

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I did not bother 'seeing' the oil. I just sucked out what was not needed. A hose to the correct depth and some type of suction and you are in business.
 

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If you hold the wood dowel to one side (lets say the left side 9 o'clock position) and slide it down. Then pull it out while maintaining the left side contact and not spinning the dowel, you should be able to read the right side of the dowel and see what the level is.
 

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Discussion Starter · #13 ·
herk, I have a copy of the actual Kawasaki KZ750 series service manual. There is a suppliment in the back for the 1982 models, as mine is. It states that dry, rebuilt KZ750H forks (not the R series) should have 308 +/- 4cc's of oil, and that the level of the oil should be 436 +/- 2mm's below the top of the tube with the springs out and the forks fully extended (not compressed). It states that the oil level height is more important then the actual amount of oil used.The free spring length limit is 483mm (or roughly 19-1/32").

I'm going to try spraying my metal rod with flat white paint today and see if that helps.
 

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I used a clear piece of 1/8" (or so) plastic hose glued on the end of a plastic syringe (used a turkey baster first time), taped to an aluminum rod that has been marked with a file exactly xx" from the end of the rod and hose.

Dump some oil (too much) in the fork tube, stick the homemade fork tool in the fork until the file mark is even with the top of the fork, squeeze the turkey baster (or pull out on the syringe) and let it suck out all the fluid it can. Then do the same to the other fork. Fork oil level will be exactly the same in both forks, and will be at the exact specified level.

Hey, my eyes aren't as great as they used to be either! :)
 

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herk, I have a copy of the actual Kawasaki KZ750 series service manual. There is a suppliment in the back for the 1982 models, as mine is. It states that dry, rebuilt KZ750H forks (not the R series) should have 308 +/- 4cc's of oil, and that the level of the oil should be 436 +/- 2mm's below the top of the tube with the springs out and the forks fully extended (not compressed).
I'm anal retentive. I try to be very exact when doing things, since if I'm not, I tend to worry about whether my inaccuracy is a part of The Problem.

That said, allow me to point out that a 4cc inaccuracy on a fork tube taking 308cc's of oil, is what... a 1.something% inaccuracy? So, wouldn't a +/- a coupla mm's accuracy in a fork tube be pretty damned close? Enough said methinks. :wink:
 

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Discussion Starter · #18 ·
steell, I can see that idea, and it's the best one yet (kawpaul, sorry if you said the same thing and I didn't catch it). The vacuum would suck the oil level down to where ever you set it at, and not remove any more. I have all the stuff and will make the thing tomorrow. Thanks again all who responded!!
 

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Hello all:

Has anybody noticed any kind of fork sensitivity associated with oil level? My gut tells me plus or minus 10 to 15% of the specified oil volume/height should not make much difference in damping, wear, noise, response, and/or seal life. But I've never experimented.
 
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