Tach seal leak

Hello, I have an 80 KZ750 LTD with a leaking tach cable. I have read through the forum on fixing this, and I understand it is a common problem. I am going to go the quick fix route by using a 10mm o-ring or a card stock gasket first, before I replace the seal or tach drive. My question is where, specifically, does one place the o-ring? Does it go in between the flange of the cable and the tach drive, or does it go in between the flange and the knurled nut? If it just sits in between the flange and the drive, how do i ensure that it makes proper contact as i tighten the knurled nut? I understand I can use a cereal box to make a paper gasket, and I assume that it would go in between the flange and the tach drive housing as well, yes? Thank you.

Do yourself a HUGE favor and replace the oil seal, o-ring, and gasket all at the same time. All together the cost of the parts is only $10, so it really is not worth fiddling around doing a piece-meal job when you can solve the problem for so little $$$. Ed

Thank you, Ed. I do plan on replacing those parts at some point during the winter, but right now I really just want to try a quick fix to make the tach stop leaking all over my exhaust. My time to work on the bike is very limited and it is a daily driver. I understand that to take the tach drive out it has to be tapped out from the inside, and that is not something I have time to mess with right now.

I guess the confusion is on my part. You asked where the 10mm o-ring goes. It goes on the tach gear guide (the o-ring is the part labeled "13" in diagram below). So I don't see any way of replacing it without pulling the guide; that's why it seemed logical to me just to replace the other pieces at the same time since you will already have it apart. Clearly, I'm missing something. Ed

www.kzrider.com/forum/4-electrical/5974-tach-cable-leak
Look at your reply about halfway down.

www.armbell.com/forum/viewtopic.php?t=76...27d90dd&mforum=kz400
Here is another thread. There are other alternative fix threads out there as well.

Now I understand your o-ring question. I cannot speak to the second link you gave, but I can tell you about the first link because that was my posting.

I put a small o-ring under the tach cable knurled collar. I thought that was a pretty slick fix. Unfortunately, it didn't hold up well. It temporarily appeared to stop the problem, but what actually happened was the oil continued to leak from the engine but rather than dripping out it crept up inside the tach cable between the inner cable and the outer sheath. This didn't really hurt anything as the oil never went all the way up to the tach. However, once it accumulated to a certain level it did begin leaking out around the knurled collar again. I ended up pulling that o-ring out and replacing the appropriate parts (about 11-12,000 miles ago) and it has not leaked since.

If you are looking for a temporary fix that approach should be helpful; just keep in mind it is temporary. Ed

I have done this repair (correctly) and the entire process, from start to popping the top on a malt beverage, takes 2-3 hours for the uninitiated. I see no reason to do it any other way, since doing it correctly means another 20-30 years of leak-free riding.
But that's just me, I'd rather do it correctly the first time and ride for the rest of the time.

koolaid_kid wrote: I have done this repair (correctly) and the entire process, from start to popping the top on a malt beverage, takes 2-3 hours for the uninitiated. I see no reason to do it any other way, since doing it correctly means another 20-30 years of leak-free riding.
But that's just me, I'd rather do it correctly the first time and ride for the rest of the time.

+1 That's the lesson I learned after trying my home remedy. :laugh: :laugh:

So, to replace the o-ring and seal I have to pull the drive assembly, part 14 in the diagram above. Do I have to take the valve cover off to tap it out from inside, or can I pull it out from the outside once I remove the hex screw? Also, if I just replace the seal, I can do that with the drive still in the head, correct? Just remove the old seal and replace. Thanks, you guys are great!

Remove the cable (duh).
Remove screw 20.
Part 19 holds the drive assembly in the head, it comes off when you remove screw 20.
You will want to remove part 14 (not sure of its name). Just tug on it, it will come out, but may protest due to sleeping there for the last 30 or so years.
Replace o-ring 13 and seal 15. I don't remember whether 16 needs to be replaced or not (did it in 1998, so I have slept since then).
You are now ready to reassemble and go riding again.

Notes: 12 may come out with 14, but that is O.K.
Head and valve cover stay on the engine.

Best of luck.

When I did mine I had the valve cover off to check the valve clearances, so I don't know if removing the cover is absolutely necessary or not.

The screw (part #20) can be VERY stubborn! You can make removing is MUCH easier if you soak it with Kroil or some other high quality penetrating oil for 2 or 3 days before attempting to remove it.

If the screw on your bike (part #20) is a cross head screw (they are actually JIS not Phillips even though they look like Phillips) take a look at the link below. It describes how to deal with that and other crosshead screws on the KZ. A regular Phillips screwdriver will deform the head and may prevent you from removing the screw, but the link shows how to prevent that. Ed

kzrider.com/forum/21-tools/532335-budget...ewdriver-tips#532335

I just did the one on my bike. I was confused about what seal was what also so I took pics knowing they would come in handy to post here. I have a different model bike but same seal setup.

Z1Enterprises has all the three seals you need. You will have to call them for the fiber washer (red) part. They don't show it on their site but can get it. Also, all these parts are still available from Kawasaki.

Here is the tach drive still in the bike.



Remove the JIS screw, mine was tight so I used a 1/4" ratchet with a 1/4" socket to hold a Phillips bit that I modified like 650ed posted. Works great. That screw was darn tight so be sure to not strip it. That why I use the ratchet on really tight screws, you can apply a LOT of inward force while turning it. Once the screw is out the retaining plate comes off. Then to get the tach drive body out I used a 21MM socket (I think it was 21) to turn it a little to get it moving, then just worked it out. Took some tugging and turning but it comes out. You do not have to pull the valve cover. Not on my bike anyways.



Once out the tach drive gear slides out the back. On mine the old seal was STUCK in the body so I put it lightly in a vise and used a drill to grab the old seal and pull it out. Be careful to not damage the inside bore of the tach drive!

These are the three new parts you need. The 0-ring for the body, the lip seal for the tach gear shaft itself, and a fiber washer that sits inside the end of the tach cable.



The lip seal goes with the spring end IN toward the motor. Do not drive it in too deep or you will crush the lip/spring section and ruin the seal. Check the shaft of you tach gear and if there is a worn spot (groove) where the old lip seal was riding on it, you can either clean it up, or, press the new seal in to a shallower/deeper depth so the new lip will ride on a new section of the shaft. Luckily the body is quite deep so there is plenty of room to put it in a different position/depth than where it was. Remember, not too deep or you will ruin the seal!

Put some oil on the shaft and 0-ring before putting it all back together. Should seal up just fine. With it done correctly it will not leak even without a tach cable hooked up.