jumps out of gear

my zl shifts slicker than greased snot cept zzzzzzzzzzzzzzzzziiiiiiiinng into 5th.
foremost, el lazy foot is a culprit, because by then we r near the 1 ton mark, and the butthole puckers a tad, but likely there is a weekspot in the mechanism that contributes, any opines on ferreting out the offending wascall!!!!! short of a caddyshack vendetta?

Jeff, For the benefit of older geezers like myself, at least in the tech forum, try to word tech questions carefully and in simple terms for ease of understanding. It will help you get more answers if you are indeed interested in getting answers to your questions...

If I read your post correctly, the bike is jumping out of 5th gear? Where does it jump to? Neutral? False Neutral?

In any case, one of two things can be wrong:

1. shift forks or gears are worn. To fix this you will need to split the engine cases. This will require pulling the engine and scraping all case gaskets. You then remove the top case bolts and bottom case bolts and flip the engine over. You will then split the cases and pull the transmission and inspect the forks and gears. To repair, you will either replace stuff or get the gears undercut. Any bike machine shop can undercut gears.
2. shift drum detent mechanism not working properly. The shift drum is under the inner countershaft sprocket cover. On the upper right on the engine cases is a banana shaped piece of metal that has a spring attached. Its purpose is to keep the shift drum from moving. If the spring is weak, this mechanism will allow the bike to jump out of gear. You may also have a worn peg on the drum. The pegs are very specific to the gears so a worn peg can cause the bike to drop out of gear. Buy a new spring and install it on the detent mechanism and remove the round disk plate from the outside of the drum and get a new peg and replace the worn peg. There are about 8 pegs with the longest associated with neutral (it contacts the neutral switch). Best bet is to buy a new set of pegs and replace all. If replacing the spring on the detent and putting new pegs in doesn't help, the problem will be in the transmission and you will need to do step 1. You might also get a new external shifter spring and install it at the same time as you may not be getting the shift pawls in position on the shift drum and the pegs may not be pulled all the way... the external shift spring goes over the shifter and has four loops for your bike I think. Make sure you use the correct replacement as some of the older bikes used a three loop spring and won't work right on your bike. Get the part numbers for the springs and shift drum pegs and contact www.z1enterprises.com for these parts. Part numbers are available from kawasaki.com-parts diagrams. Make sure you have the FULL part number xxxxx-xxxx form.

well thank you george

I actually had a case where my crankcases developed cracks in the input and output shaft bearing locating dowels. This caused bike to jump out of gear in 3rd, 4th and 5th gears but would not do it in 1st or 2nd. Not a "normal" diagnosis of jumping out of gear.

RSN - Locating dowels for the transmission? Hmmm... there are slots at the ends of the shafts where the little moon shaped things sit between the transmission and cases but I am trying hard to recall dowels on the transmission... I know there are locating dowels on the crank but can't recall them on the transmission. How did they crack? Did you take any pics? Never heard of this...

weak shifter detent spring
worn shift drum
bent / worn shift fork
chipped/worn gear set dogs

could be one or a combination of any

Post edited by: trippivot, at: 2006/08/03 11:52

I believe was actually dowels on drive and output shafts bushings not bearings, sorry.

Picture HERE

You can see the dimple on part 44.

HERE

Dowel is part number 23.

May have been caused by using momentary kill switch to kill ignition when speed shifting. Timing may have been off and caused to much preload on tranny before actual shift. Started to drop out of gear just after tried that particular mod. Not normal, KZ's known for beefy bottom ends.


Post edited by: RomSpaceKnight, at: 2006/08/03 19:52

Post edited by: steell, at: 2006/08/04 17:21

Oops link does not go far enough. Bike is a 77 KZ900. Part 44 is in tranny and the dowel is in crankcase.

Not relevant to the thread anyhoo. Sorry if any one thinks this is a hijack.

Post edited by: RomSpaceKnight, at: 2006/08/03 20:52

Actually, the locating dowel cracking and causing the bike to pop out of gear is perfectly on topic and an EXCELLENT piece of info. I had forgotton the dowel you refer to and the dimple in the shaft that it seats in. If I have this correct, the dowel fractured and the shaft was able to move around a bit? Dang... if you were inspecting the transmission from below (pan), you would NEVER catch this... would be pretty easy to catch if you split the cases though. That must have been darn hard to figure out when it happened! How do you think the dowel cracked? There isn't much load on it so it may have happened when the transmission was installed and the cases rejoined?

clarify for the mechanical dullard, would a cracked dowel be symptomatic of a single gear, as in my case(5th)or would the problem be more varied?
i had a valkyrie that was weak 1 gear below top right off the showroom floor. under throttle it would go into a false neutral or occaisionally thud into top. i had a v65 magna that again was weak one below top , but only went into false nuetral.
my cb900f was weak in 2nd, prone to false neutral.
my fj1200 was prone to false neutral 2nd.
now my 2nd valkyrie was similar to 1st, false neutral one below top, or shifting self into top, but the problem has disappeared for the last 10k or so.
i have described these symptoms to mechanics and have been told they are mechanically impossible. after 20 yrs on the street i have come to accept the flukes as peculiar to a particular machines.

some say my shifting technique is flawed. i never, ever missed a shift on my klr650. that bike shifted so well i sometimes went clutchless, which i have never done on any other bike

Check buykawaski.com for your zl100. See if the tranny has locating dowels on the input and drive shaft bushings. If they do not exist then you are looking at other problem.

I found problem when I went to replace my tranny with a used undercut Orient Exprees tranny. That is when I found the cracks.

The cracks where in the crankcases not the dowels. There was some wear to my original tranny and shifter forks and the undercut was a good idea. That put an end to my racing (1993). After buying tranny and then having to come up with another set of crankcases I ran out of money. Followed by becoming unemployed for over a year. Only now do I have a garage to rebuild the dragbike.

I always thought that general wear and tear on trannies eventually showed up in the shift from 1st to 2nd when the most torque/power was being fed into tranny (from hard launches not power/torque output curve). Plus the extra gap for neutral. That was why I first suggested the cracked case scenario. My dragbike held up fine launching. It was most of the way down the track before it let go.

When it comes down to it, my issue was a rare case. I would suspect you have a more common issue.

My ZX11 has a tendency to drop into neutral if I do not make a good positive upshift from 1st to 2nd. I am hoping I am not soon to encounter tranny issues with that bike. Am currently dealing with worn out cams and rockers (1500$CDN WEBCAMS, 3500$CDN dealership).