Removing the front fork top plug

Hi all, could someone tell me how to remove the top plug on the front fork so that I can change my fork oil. I have an 81 KZ750H. I removed the drain screw and drained the old oil, and I can't figure out how to get the cap unscrewed at the top...any advice?

chrispysaki wrote:

Hi all, could someone tell me how to remove the top plug on the front fork so that I can change my fork oil. I have an 81 KZ750H. I removed the drain screw and drained the old oil, and I can't figure out how to get the cap unscrewed at the top...any advice?

Here's a pic for reference from kawasaki.com.

Before attempting to remove the fork cap, be sure to loosen the bolt that tightens the clamp around the top of the fork.

Good Luck!

[Click on image to enhance view]

Don't forget to bleed off the air if you have air assist shocks in the front(which it looks like) before any maintenance or oil will spray all over.

Thanks for the tips. Hopefully I just need to loosen the bolt holding on the fork, cause I wrenched on that top cap with a plumber's wrench as hard as I could and it wouldn't budge. For reference, I was trying to loosen part 44029/A. I did let the air out as well.

I loosened the bolts holding the forks and slid the forks down a couple of inches. Didn't have any problems unscrewing the caps with a large cresent wrench

Ok, so I loosened the triple tree bolts holding the fork tube, slid the fork up a few inches and still nothing. I don't know if you can tell from the pics, but I've stripped quite a bit of metal off these top plugs trying to unscrew them with a plumber's wrench (don't have a crescent wrench).

Is there something I'm missing here? Are they reverse threads or something like that? I thought this was going to be an easy job, but it's turning out to be the most frustrating thing I've done yet with the bike.


Here's a photo with air valve still installed

chrispysaki wrote:

Ok, so I loosened the triple tree bolts holding the fork tube, slid the fork up a few inches and still nothing. I don't know if you can tell from the pics, but I've stripped quite a bit of metal off these top plugs trying to unscrew them with a plumber's wrench (don't have a crescent wrench).

Is there something I'm missing here? Are they reverse threads or something like that? I thought this was going to be an easy job, but it's turning out to be the most frustrating thing I've done yet with the bike.


Here's a photo with air valve still installed

Be sure to leave the clamp bolt remaining loose before attempting to remove the fork cap.

Could also tap on a screwdriver used as a wedge inside the crack to very slightly enlarge the clamp area.

Could also employ dry ice applied to the cap just before attempting to unscrew it.

Or while applying unscrewing pressure to the cap, have an assistant heat the fork tube with a propane torch.

I believe it is standard thread, not reverse thread.

When the cap was last replaced, the fine male threads might have been cross-threaded. :pinch:

Good Luck!

And please get a proper wrench. The pipe wrench might be simultaneously gripping the fork tube.

Remove the forks from the bike, then apply some heat w a propane torch. Use a 22mm wrench or crescent wrench. You may have to use the triple tree as a clamping device so that you can remove the caps. I use a spare triple.

And they are regular threads - righty-tighty, lefty-loosy.

Also, to make the job less messy, afte removing the cap, I dump out any remaining oil, pour in some solvent & reintstall the cap, invert a few times, then proceed w the job. This is assuming your oil is as bad as most people report.

If you were to remove the air valve from the cap, how large is the threaded opening? If it's relatively large, could you screw a long bolt with the correct thread size into the hole and use the bolt as a lever to unscrew the cap? Ed

My idea would be to slide the fork up even further and re-clamp the bottom triple tree bolts so it is held like a vice in the tree and clears the end cap. You should also use said "tapping screwdriver into top clamp gap" method to spread out the clamp fully.
You need more leverage than a pipe wrench is going to give you- a longer implement. I used a three foot iron pipe fitted onto a 1/2 " socket to loosen mine the first time-they were so tight. Once loosened, they come in and out like butter now (just changed fork seals). Might as well do that too while you have the mechanism off. Maybe you could try some sort of ball joint remover to put the air valve between or something similar. Since you have already gnashed the aluminum, you could use a vice grip with some kind of pipe fitted on the end.
In any case, you need leverage! My two cents

650ed wrote:

If you were to remove the air valve from the cap, how large is the threaded opening? If it's relatively large, could you screw a long bolt with the correct thread size into the hole and use the bolt as a lever to unscrew the cap? Ed

ABSOLUTELY NOT, you will destroy the cap. It just takes a lot of elbow grease to loosen the caps. When you put them back, you do not have to tighten them so much. They have an O ring on top and they will not leak if just tightened reasonably snug. First of all remove the air cap fitting so if you slip you wont brake it off. Using the proper size wrench, put it on the cap and give it a good whack once or twice with a rubber mallet to brake it free. This will NOT loosen it. Now, applying even constant heavy pressure, start pulling on the wrench. It might take a minute or two of constant pulling, AND I MEAN PULLING, If you weigh 130lb soaking wet, forget it get someone who can put some weight into it.