1976 KZ400 D3 Restore Project

Hey Gang,

Im starting to work on the 76 I bought last month, and instead of posting a bunch of random threads, I decided to start a new project thread and keep everything tidy. I have a feeling the left piston and/or cylinder is screwed up due to a lot of carbon/oil seepage. I do have the 77 motor, and I am thinking about using parts from that, if possible. 99 psi on the left and 149 on the right. Looks like the head gasket has been leaking for some time. I have a new one here. 14k miles on the speedo. I was born in 76 so Ive been looking for a birth year kz for a while. I need 1, preferably 2 airbox to carb boots, having a hard time locating those. The front brake works great so thats a bonus.

I like it! Keep em coming!

Been working in my basement organizing tools and such, and started tinkering with the 76. I def am going to have to find boots or use some radiator hose or something...

Great news gurus! I found a pair of NOS airbox boots. They are located in Denmark, shipping to Netherlands (Ill be in Europe in a few weeks) and I can pick them up. Im going to the shop to work on the 75 today, Im hoping to get the measurements for the Pilot rubber caps from the carbs. Good morning and have a great day

I dig that seat cover

So I started looking around for problems on the 76. I left the service manual at the shop, so I didnt dig as deep into the top end as I wanted to, but I found a bunch of wiring problems, and got a couple broken bolts out. There are 2 wires from the harness to stator area that were frayed/grounding on the chain/front sprocket. Got those fixed up. Someone in the past spliced an extra ground jumper from the starter solenoid to the fusebox for some reason. It was taped with masking tape of all things...if this weather would warm up, I could actually scrub this thing down and start getting it cleaned up.

Started wrenching on this around 430am this morning. Got the top end off, but as I was taking the cam tensioner off I noticed a few broken plastic pieces. Of course, one of the pieces fell into the bottom end. So after I got the motor off the frame, I picked it up over my head and held it upside down and lucky for me the broken piece fell out. Took the motor and the starter to the shop, got the starter all cleaned up and rebuilt, and started scrubbing the motor up. Im debating on whether or not to get the frame powdered...theres a decent amount of rust in places and once you get the disease of a crispy motorcycle, you cant leave well enough alone haha!

Well here is a picture of the part that fell into the motor and came out when I put the motor over my head upside down....anyone recognize it? I really dont wanna split the bottom end of this motor. Thanks!

Take a closer look on your cam chain guide !!!





www.cmsnl.com/kawasaki-kz400d3-1976-cana...t/52503.html#results

Michael

Man, totally overlooked that little part. Thanks very much for pointing that out! My next question is, how do I reapply that to the guide?

With the amount of oil that was coming up from the bottom end through the rings (moreso on the left cylinder where most of the oil was leaking from the gaskets) is its safe to say I may need new rings? I didnt ask my buddys at the shop about it yet as Im still cleaning up the parts...the sleeve looks fine on both, after I cleaned the pistons up, they also look fine. For the 400, I can get standard size...then .020 or .040. Sorry for the novice question, Ive only rebuilt 2strokes in the past (which is a cakewalk). The valves were hella dirty, but I got them also cleaned up nice. I didnt take them apart, but started doing research and seen that the valve stem seals are also a common problem on these motors. Train of thought is "well you have the motor apart, might as well replace what is commonly worn out" ...

I would say the oil comes through the valve guide seals.
If the head was apart do renew the seals and do a light clean on the valves with a valve/valve seat lapping.
Always use a condom over the valve stem for the new valve seal install to prevent a damage of the seal lip (#4)
by the valve keeper groove and use the right tools for it!!!!