Shortened fork oil level

Hi guys,

I have a KZ750 LTD and shortened my fork a couple inches by taking out the spacer at the top like I've read (I might make short spacers if it's bottoming out or I need more clearance for the front wheel under braking).

However in my searching, I haven't come across what this does to the desired oil level in the forks. Should it be lowered by the height of the spacer so that when the bike's weight is on the fork, the oil level is the same distance from the top?

Thanks for any advice!

P.S. I'm assuming the range of air pressure stays the same as before, but let me know if I'm way off on that assumption too!

Id try it with original amount of oil,but maybe a little thicker to help keep it from bottoming out so easy.
You can always take some oil out if its too stiff I suppose

I was thinking of trying the thicker oil for that reason. I was just wary of using too much oil, since it sounds like that can wreck your fork seals (so sayeth the manual, but maybe they're paranoid). I suppose I can start with a low amount of oil and add more to stiffen it up as needed.

I would stay close to recommended level and go heavier as was mentioned. Can get pretty harsh with too much oil.
Wayne

Right, I was just thinking that the definition of "recommended level" is a bit different since having the oil X distance from the top with the tubes fully extended, will now put it a couple inches (the height of the spacer) closer to the top once the weight of the bike is on it.

So I'll probably start a couple inches down and add oil to firm it up if need be.

You can try reducing the oil by the percentage you lowered the forks. Add if needed.

better to wreck the fork seals than the inner workings of the forks by bottoming out to much maybe

Raising the oil level will basically increase spring rate from what I have read. The air in the system does the same but air compresses more than the oil. That is why to much oil can make a harsh ride. There will be a happy medium I hope. Good luck.
Wayne

another idea for shortening them would be to slide them up to your handlebars in the triple tree.

figure out how much oil consumes the space youve lowered it and subtract that from recommended fill amount. if your fork tube inside diameter is lets just say an inch and three quarters and you dropped it lets say 2 inches, find out the liquid displacement for that area. could use a clear tube or even the fork leg itself if your crafty to figure it out. thats really over thinking it tho imo. best of luck

lushbaugh wrote: figure out how much oil consumes the space youve lowered it and subtract that from recommended fill amount. if your fork tube inside diameter is lets just say an inch and three quarters and you dropped it lets say 2 inches, find out the liquid displacement for that area. could use a clear tube or even the fork leg itself if your crafty to figure it out. thats really over thinking it tho imo. best of luck

he is right you know, the level should be pre measured or checked with the forks fully extended.

Thanks for the input guys. I finally got a chance to get going on this and ran into something else strange - the manual I have mentions the oil level in both inches and mm, but it turns out these are way different than each other!

It says 14.7" or 436mm. 14.7" is actually about 373mm, and 436mm is actually about 17.2". I checked the owner's manual, and did a bunch of searching, but couldn't figure out what the correct height was. Anybody know what the measurement should be so I can base my calculations off that? Thanks again!