High RPMS in 5th gear/ kz400?

Hello all. I was hoping some kz400 people could give me some input. I got my bike on the freeway for the first time since the rebuild and it ran pretty good., and was quite a feeling going WOT on the thing for an extended period of time. My only concern was that in 5th gear at about 70 MPH (my speedo doesn't work very well) I was running at about 7,000 RPMS. I might have been going faster maybe 80, I'm not sure. But If this thing in theory should do 100 -110 mph then 7,000 rpms at this speed seemed to be a little to much. I wouldn't think in 5th you couldn't get to the redline which is 10,000 rpms on my tachometer. My question is, is this normal? Could you bow up a bike in 5th gear? Maybe it has something to do with the pods and the rejetting (I've got a 150 main in there). I'm pretty sure the sprockets and everything are stock, why would I get such high RPMS in 5th? Clutch maybe...I really have no Idea... maybe it's normal? Any Ideas?

Sounds like your clutch may be slipping. If you haven't already done so, try adjusting it using the instructions in the Kawasaki Service Manual. Ed

650ed wrote: Sounds like your clutch may be slipping. If you haven't already done so, try adjusting it using the instructions in the Kawasaki Service Manual. Ed

yeah ed.. thats on my to do list for tomorrow. I have a new clutch cable and Friction plates ready to go. I'm a little nervous to do the clutch work.. but I've done everything else might as well keep going, it's worked out so far. Should changing just the friction plates be good enough? or should I replace everything? Really no way to know I guess until I open her up.

thanks ED

Before opening up the clutch cover try adjusting the clutch using the manual. You may find adjusting it solves the problem and that you don't need to replace the clutch friction plates. If you find it still slips, replacing the friction plates should be enough without replacing the steel plates, but check the steel plates to make sure they're not warped. You may also want to replace the clutch springs - new stock ones will do just fine; no need for heavy duty aftermarket ones. Before you tear into a a clutch job be sure to have the correct tools - especially a torque wrench that is of the correct calibration range for the clutch springs. Have you read the posting regarding JIS screws / screwdriver bits and about JASO-MA oil specs? If not, check this out as it may save you some headaches. Ed

kzrider.com/forum/10-new-members/580406-...biker-from-mn#580410

mark your sprocket and count number of teeth (front & back)
maybe we can get a ratio here

man that would be neat to see kz400 74 i had one i ran the piss out of that thing on highway back and forth to work

650ed wrote: Before opening up the clutch cover try adjusting the clutch using the manual. You may find adjusting it solves the problem and that you don't need to replace the clutch friction plates. If you find it still slips, replacing the friction plates should be enough without replacing the steel plates, but check the steel plates to make sure they're not warped. You may also want to replace the clutch springs - new stock ones will do just fine; no need for heavy duty aftermarket ones. Before you tear into a a clutch job be sure to have the correct tools - especially a torque wrench that is of the correct calibration range for the clutch springs. Have you read the posting regarding JIS screws / screwdriver bits and about JASO-MA oil specs? If not, check this out as it may save you some headaches. Ed

kzrider.com/forum/10-new-members/580406-...biker-from-mn#580410

Yeah I have tried adjusting the cable without much luck..It's really old and stiff. I can visual see it fraying at the lever. I have anew one so doing that is a must at this point. I will hold off on the friction plates for a bit I guess. But it has 21k miles and I doubt it has ever been replaced. Thanks for the link!

P21 wrote: man that would be neat to see kz400 74 i had one i ran the piss out of that thing on highway back and forth to work

Oh man, it's been super fun rebuilding and riding this thing. You wouldn't believe the amount of people that stop and look and say something like you.. ("I had one of those in the 70's.). It's cool. I have to say, I'm really glad my first project was a KZ400 and not a honda CB350 or something. I see the CB's all the time but rarely see a KZ.. Not sure why.

so far as the sprocket count. Would a sprocket with more teeth give me lower RPMs or vice versa? I always get confused on gear ratios.

I have to lean towards Ed's clutch slippage Idea.. I know the clutch is in bad shape. I can rarely find neutral when Idling..and it;s ralmost impossible to shift into neutral or out of first when Idling... the shift shaft just will not move.

recez wrote:

650ed wrote: Before opening up the clutch cover try adjusting the clutch using the manual. You may find adjusting it solves the problem and that you don't need to replace the clutch friction plates. If you find it still slips, replacing the friction plates should be enough without replacing the steel plates, but check the steel plates to make sure they're not warped. You may also want to replace the clutch springs - new stock ones will do just fine; no need for heavy duty aftermarket ones. Before you tear into a a clutch job be sure to have the correct tools - especially a torque wrench that is of the correct calibration range for the clutch springs. Have you read the posting regarding JIS screws / screwdriver bits and about JASO-MA oil specs? If not, check this out as it may save you some headaches. Ed

kzrider.com/forum/10-new-members/580406-...biker-from-mn#580410

Yeah I have tried adjusting the cable without much luck..It's really old and stiff. I can visual see it fraying at the lever. I have anew one so doing that is a must at this point. I will hold off on the friction plates for a bit I guess. But it has 21k miles and I doubt it has ever been replaced. Thanks for the link!

There's more to adjusting the clutch than just the cable. I'm not specifically familiar with the clutch on the KZ400, but take a look at the manual and I think you will see (if it's like most other KZ models) 3 different places for adjusting the clutch. There should be 2 places on the cable and 1 at the clutch release under the engine cover. If you only adjust the cable you aren't adjusting the clutch push rod, so you may not get full use of the clutch. Ed

You can download the manual from kz400.com. Check out the rest of the site too. It was all created by one man, Odd Ivar Bekkelund. He has since passed away, but left behind a huge wealth of information. Others from the 400 forum have taken up his work and maintain his site now.

www.kz400.com/WorkshopManFrameset-5.html